Antirrhinum hispanicum (Perennial Spanish Snapdragon)but I dont think the leaves are right for that, they look more like Fuchsia?

I think its balsam and will seed everywhere if you don't pull it out as the seed pods explode spectacularly.

Sorry Drc, it's not any kind of antirrinum - it's Himalayan Balsam (Impatiens glandulifera). A notorious weed for spreading wildly. I'd get it out before it can shed any seed at all, as it's really invasive.

I'm agreeing with DRC726, it is a variety of Snapdragon - going with flower shape and leaf.

oddly enough I have one growing in my garden that I did not specifically buy (bought wild flower seeds!). They are annuals that self seed well. Deadhead if you do not want them to come back. Personally I think they look good in a border.

Beattie has it right.

Look at the images on http://www.languard.co.uk/invasive-weed-management/himalayan-balsam/

Sorry Kildermorie, it's not a Snapdragon. Google Himalayan Balsam and you'll see that that is what it is. You may well have one in your garden, but it's still Himalayan Balsam.

Thank you, Thepoisongardener! Posted at the same time.

I had a look and its got the serrated leaf edge of the Himalayan Balsam. Each plant produces over 2000 seeds which explode and propel the seeds up to 5 metres, no wonder it spreads!

Oh dear! Damn those wild seeds!

I also think it is Himalayan Balsam, I have recently been looking up Balsam as I had some seeds (but they are rose balsam which is alot different) and came across loads of pictures of this plant. It's nasty, get rid before it seeds.

definitely himalayan balsam. the seed pods swell and explode, throwing seed up to 10 m away fro the parent plant. Trust me on this I had one plant [dont know where from] and the following year 100's of seedlings up to 10m away. on the plus side they are easy to pull out and compost well. [dont compost the seed pods though]

Definitely Himalyan balsam. I had it in my garden and it seeded itself all over the place, even in the lawns. The seed heads tend to 'explode' when you walk past the seed heads and you can feel the missiles hitting your arms and legs (scared the willies out of me!). It's a thug, get it out!

Isn't this the same stuff that is spreading along our river banks and suppressing our native species? Pretty, BUT...!

That's the one, Pennyfarthing :-(
It doesn't seem quite as bad as Japanese Knotweed, but it's on the same page.

Thanks for all the comments and feedback.
Definately can say it is Himalayan Balsam and time to pull it out before we get shot with exploding seed pods!!
Stephen