Times have changed. Her allegiance used to be to the Workers' Revolutionary Party, whose battlecry in the heady days of class warfare was "Labour and the SDP, the running dogs of the bourgeoisie". But now Ms Redgrave feels that it is the Liberal Democrats who offer the best hope for ushering in a more just, and fair system.
That is not the only change. Ms Redgrave believes that faced with what she sees as an authoritarian Conservative government introducing draconian legislation leading towards a police state, society has two bulwarks of defence - the judiciary, and the press. One of her main references to support her views is The Economist, a publication that has never been seen as a bible of Marxism-Leninism.
These new favoured institutions, of course, featured prominently in the demonology of the hard-left in the past. WRP leaders like Gerry Healy regularly lambasted these "arms of the state" trying to destabilise and destroy his organisation.
However Ms Redgrave remains a member of the Marxist Party which was launched 10 years ago. And she says she is "extremely alarmed, and angry" at the way the Establishment is running the country.
But the Marxist Party is not putting up any candidates. And Ms Redgrave is a passionate opponent of the law and order measures - the Criminal Justice Act, the new Police Act, the Crime Sentences Act, and the Asylum Bill - being brought in by Michael Howard. She is a prominent member of the lobby group set up to oppose this, the Charter for Basic Rights.
Ms Redgrave said: "I spoke to Paddy Ashdown a few months ago at the House of Commons when I was there for a meeting against the Asylum and Immigration Bill, which is an apalling piece of legislation.
"He assured me the Liberal Democrats are opposed to it, and I believe him. So I shall be voting Liberal Democrat at my constituency of Brentford and Isleworth.
"I shall also be speaking to the Labour candidate there, but the Labour Party has done very little to oppose any of these very unfair measures brought in by the Government, so I cannot see how I can vote for them."
Ms Redgrave, 60, the scion of one of the most famous thespian families of the country, and described as the greatest British actress of her generation, continues to speak out against what she sees as injustice.Reuse content