You have only one question posted, which is this one. Likely the photo you tried to post was, indeed, too large, they usually have to be reduced in size for this site.

What you suggest is not a good idea at all, I'm afraid. It would be useful to identify the plant properly - from the distance you've taken the photograph, its hard to tell what it is, particularly as there are no leaves present currently, although it does seem there may be some flowering or budding just starting at the top. With a proper ID, it would be easier to decide what to recommend regarding trying to get straighter growth, so maybe you could post another pic or two later when more identifying features (leaves, flowers) are present?

Also you need to decide whether you want a double trunked tree because at present you have another long shoot coming from near the base. If you leave that in place it will thicken and bush out at the top and balance the tree so it will look OK.
If you are trying to straighten the original trunk I would have tied it higher up, just before it branches for the first time. Then if that works you could remove the second trunk, but only do that when he tree is dormant.
Best do nothing until you've done what Bamboo suggests.

Do you think it might be a Cornus ladies? I think if it were mine I'd remove that secondary stem right at the base and tie it higher as Stera suggests. Its not that bad, I think it would be ok in a year or two if it were tied in higher up the stem.

Not necessarily - could be Prunus cerasifera or even Cotinus royal purple, or a few others, no way of knowing without seeing foliage and a closer image

Thank you for your helpful comments. Sorry for my delay in answering, but it was my birthday yesterday, so other things on my mind.
I'm not sure if it fits the cornus description as the flowers look different to mine, although there must be many different varieties of them. It has started budding, but I don't know if a photo of them would help. It's raining at the moment, but when it stops I'll take a photo and put it on. I'll also have a look on Google and my sister in law is looking through her books and will text me with an answer if she finds it. She remembers the plant, but not the name. Again many thanks for your help.

ah, well, many happy returns then...

A bit more info. My sister in law has come back to me saying it is cornus variegata, common name is dogwood.
I have put a couple more photos on. The leaves at the base are a wild bramble which is tangled in with the root. I've sprayed the leaves and it looks like it's dying, I hope.
Many thanks for your help.
Just tried to add photos, but nothing to click to do it, sorry.

Thank you Bamboo, although at my age they are best forgotten.

Tell me about it, I far prefer to ignore my own now...

Cornus variegata usually means Cornus controversa 'variegata', common name Wedding Cake tree because of its tiered growth habit, see link below for image

http://www.crocus.co.uk/plants/_/cornus-controversa-variegata/classid.968/

To be honest, though, your tree has not grown in an 'orderly' fashion and does not look as it should, IF that's the variety your sister thinks it is - there are other Cornus with the 'variegata' bit in their name though, and many other varieties it could be - Cornus alba 'Elegantissima' or Cornus mas florida variegata, and these have different growth habits. Establishing precisely which variety it is would be very helpful - if its Cornus controversa, in theory, it shouldn't be cut down, but if its a different variety, it might be better to cut it right down and let it regrow.

Thank you Bamboo, I'm 37 if I read it in a mirror.
I've looked at your link and the third of the three pictures look just like it, the leaves are the same and the flowers come out quite late and look the same as the ones in the picture. The shape is different and before I pruned quite a lot of branches off it was very leggy. The fir tree that was above it was very large and I have drastically cut the top off and most of the front. The shrub was underneath the bushed out fir and seemed to grow out over the lawn. I cut a lot of the shrub branches off and this cleared the overhang on the lawn. The wedding cake tree sounds very nice. I have taken a photo of an open bud, but don't know how to add it. The only way I can think of is to put the question on again, would this be allowed?
Thank you.

Yes, you can post it separately, or just post the photo in your photos section and tell us when you've done it, we can have a look at it there.

However, one thing - although you say the leaves look the same, the leaves look exactly the same on Cornus alba 'Elegantissima', so I'm still not 100% convinced that what you've got there is Cornus controversia - unless you noticed a distinctly tiered growth habit before you cut it back. The topgrowth now present is showing no sign of a tiered growth habit, it does grow in tiered layers, as in the images, so if yours never did that, and isn't now either, I suspect its a different variety of Cornus. Can you remember whether, when you bought it, it looked like a small tree, that is, with a distinct central trunk and all the growth coming off that? And although you say it flowers late in the season, Cornus usually flower around mid summer...

I've tried reversing the numbers of my age without much improvement, frankly, but give it a couple of months and they'll both be the same numbers anyway;-))

44 sounds a nice age.
I put the pictures on 'Garden Pictures' before, but I was not sure what happened with them as this is the first time I have been on this site.
We've had the plant years and I don't even remember planting it (that's the reverse 37 kicking in). The problem with the shape was the fir tree, which has dominated it's growing space. There is a main stem and another thinner stem growing from the bottom now. There was another little stem growing from the base, but I cut that one off. I took all the branches from the main shooting area when I pruned it and there wasn't any tiering that I recall, just all growing from the main bit. I'm sorry I'm not very helpful, but it had a horrible shape before I pruned it and it's not that much better now.

I've just checked your photos, and there are two images there, one showing a swelling bud on the plant. But, you know, I'd risk it and cut it down, largely because there is absolutely no evidence of a tiered branch habit and because, as you say, its not at all attractive in its current state. If its Cornus alba, they're quite fast growers, so even if you cut the main trunk down to 6 inches or less, that should force new growth this year. Give it a good few handfuls of something like Growmore, turn it into the soil or rake it in. It should produce new stems from the base and off any trunk you leave - let them grow on, so it'll be more of a many stemmed shrub than a tree. Over time, you should prune out half the stems at ground level in spring, and cut back the tops to the desired height around September, but to be honest, the only reason this is done is because new wood is coloured red, and many people want to see the red wood in winter. If you're not bothered, just keep it trimmed back at the height you want. If it is Cornus controversia, its a case of wait and see how it regrows - it might start forming a tiered habit.

With regard to the bramble growth you mention spraying, I don't know what you used, but its unlikely to kill the bramble at the root. Probably best to cut the topgrowth down, expose the woody part of the root where it joins the topstem, slash into it with something sharp and apply SBK brushwood killer to the cuts you've made (carefully - its like water, easy to spill, and you don't want it anywhere else) then cover with an upturned flower pot or something, push the soil back round and leave it. Best done now if you are going to cut the shrub down...

44 - ah, a distant memory;-))

I'm sure not too distant a memory.
Thank you so much for all your help. I think what I'll do this year is move the support further up the stem and tighten it a bit and keep tightening up a bit throughout the year. It has a lot of buds on the branches and we should have quite a good show this year. If it doesn't straighten it without support next year I'll cut it off and start again.
Thank you for the tip with the bramble, I'll get some SBK brushwood killer and have a go at that. There are other bits in open garden that I've removed the roots, but if they show again I'll treat them the same.
Again, many thanks for all of your help and suggestions.

You're welcome.