To those being glad Corbin hadn’t got in - even IF he had got rid of our nukes - it wouldn’t have made a blind bit of difference.
Err…it would make a massive difference if anybody got rid of them!
1. Anyone using one nuke knows they’ll get at least the same back. It’s called Mutually Assured Destruction and it’s what has kept them from being used so far.
Yes…because they act as a deterrent. Which you wouldn’t exist if you didn’t have any. 
2. We’re in NATO so we don’t really need our own. A strike on any country belonging to NATO is a strike on NATO, so even if he decided to single the U.K. out (and why would he, we are a very insignificant player on the stage, particularly since we jumped out of the EU, he would be buying himself nuclear retaliation.
As a rich economy, it’s not anybody else’s job to foot our bill. What if all those equipped with nuclear weapons took the same stance?!
3. Nukes are REALLY powerful. He supposedly has 7200. Less than a hundred would wipe the life on earth out in an instant. The UK has over 200 nuclear warheads, 120 locked and loaded ready to go. We don’t need that many. Corbin wanted to stop spending money on NEW ones. We have plenty. You cannot ‘win’ a war using nukes, so why keep making more? I would rather the money were spent on something we DO need more of. Like hospital beds, like free university education, like building more affordable houses.
They become more and more advanced - as does the anti-ballistic tech that shoots them down. So you would lose your edge if your weapons were lesser. Also, they require maintenance so you have to spend. Russia has many decomposing at the bottom of the sea and we’ve ended up sending in Nuvia to deal with them.