Anything to do with cutting at sizeable trees is a H&S minefield. Please take care. Maybe get a quote for the work from a qualified person.

Not seen an extendable chain saw - is she thinking of an extendable hedge trimmer?

I would have thought an extendable chain saw could be extremely dangerous... Bulba removed part of our very large ash tree last autumn, he did have to climb a ladder and this was fastened to the tree and he was also belayed. You really do need to be above the height of the branch you want to cut off to do so with any safety. We also roped the branches so we could bring them down where we wanted to rather than them slamming into the shrubs that grow around the tree.

Unless your husband is experienced at using a chain saw and is comfortable part way up a tree then as Dorjac says get an expert in.

I'd be surprised if there is such a thing available for amateurs frankly, a normal chain saw is the cause of huge numbers of serious accidents, never mind one waving about in the air on an extension...

Indeed! I am actually amazed that anyone can go and buy a chainsaw and use with absolutely zero training. They are extremely dangerous bit of equipment.

You can buy mini chainsaws but only good for small branches, they're part of the multi tool range. You can get extendable hand saws this may be better,chainsaws can bite, flesh will cut easy no second chances, not for amateurs.
I use them alot and i know lots of proessionals with missing toes, fingers and a good friend of mind which lost he's nose and an eye when chain broke, like i say NO SECOND CHANCES be carefull with chain saws

Totally agree Jiffy!

Ryobi Garden Tools have a multi tool range with small pruner attachment (like a small chain saw)but it's only as long as a strimmer or extendable hedge trimmer
Stihl make one as well called a pole pruner

Thank you for the replies and advice. The tree's lower branches were almost touching the ground so Dave decided to lop some off but some are too thick and need a saw. We may have the tree cut down completely and have contacted a tree surgeon who prefers to do it in the winter.

Dave has a should/arm problem so it is difficult for him to use a normal saw. He has used the chain saw several times but following your advice he has promised not to use it again. Thank you.

Glad you're getting a tree surgeon - expensive, but worth their weight in gold if you don't like heights - and I don't, for one.

I agree Bamboo well worth the cost.