Well, you would need a swing of over 100 seats from the actual '83 result to government, so "a few key seats" can't be responsible.

Also, once again, given a large proportion of the alliance voters prefered the tories, the number of places where their removal would have resulted in a labour victory is small- only those with very narrow margins.

Furthermore, your entire narrative relies on a partisan sense of entitlment to votes- Labour, after all, are blameless where they can 3rd, getting in your evil tories; labour can do no wrong.

You assume there was only a direct move from labour=> alliance, when in reality voters moved between all parties. The net 11% gain doesn't represent a pile of votes stolen from labour- either that or suddenly many labour supporters put them behind the tories, which is silly.

You suffered a drubbing because you put up Foot on a terrible platform which nobody wanted. Sometimes your parties (and mines!) failing are of their own making, taking their darkest hours and trying to pin it all on other people just makes you look ridiculous.