JustFloydRoad said:

Mametz said:

I don’t think that I am imagining this, but I’m pretty sure that there were vague murmurs about Charlton relocating to Milton Keynes sometime in the 1970’s.

From a Wikipedia article: Relocation of Wimbledon FC to Milton Keynes:

Relocation of Wimbledon F.C. to Milton Keynes

The south-east London club Charlton Athletic were linked with a move to "a progressive Midlands borough" in 1973, a year after Charlton's relegation to the third tier.

Southgate, Robert (5 April 1973). "Interview with Rodney Stone". The Kentish Independent. London. The Third Division club Charlton Athletic, who're in financial difficulties, might have to leave London—and go to the Midlands. They have the largest capacity ground in the Football League but their home gates have averaged only a little over 6,000 this season. They'd hoped to get funds by opening a new sports complex, but the local council of Greenwich turned the scheme down. Charlton say they've been approached by a 'progressive' Midlands borough to uproot the entire club, but they won't name the town ... Southgate: 'Forgive me, Mr Stone, but you are the General Manager of this football club. The question is however reluctantly would you consider this move?' Stone: 'If it was either the club going out of existence or moving, the answer is obvious, isn't it?' Southgate: 'You'd move?' Stone: 'Of course.'

Programme Notes 14 April 1973. There is no possibility of Charlton Athletic leaving The Valley unless we are forced out by the attitude of Greenwich Council. We wish to make this clear to our supporters who have flooded the club and the local papers this week, with letters following the announcement that we could move. The roots of Charlton Athletic Football Club are in this area ... like other professional football clubs, we have got to look to the future for ways of safeguarding the club in the 1980s. ... our plans for a sports complex and a 200-stall open market would have helped both the club and the Charlton area ... You the supporters, can make sure the club continues in Charlton by protesting as loud as you can to Greenwich Council over their refusal to grant us permission for our plans. ... the council met and discussed a scheme to site the sports complex in nearby Charlton Park on public open space. We still think this decision should be changed ...

Wimbledon allergy had a attempt in 1979 and attempt to move Luton Town (Source dated 25 Aug 1984) as well.

Of course we know Wimbledon did move for the 03/04 season*. Should also be noted Barnet and Palace were also in the running for the project. 

*- Charlton scrapped plans for a pre-season friendly vs Wimbledon due to critical reaction from fans. Tottenham and Luton soon followed.