The veteran leftwing film-maker Ken Loach has said he has been expelled from the Labour party.

Loach, whose films are regarded as landmarks of social realism, claimed the move by the party was because he would “not disown those already expelled”, and he hit out at an alleged “witch-hunt”.

It follows reports last month that the Labour leader, Keir Starmer, was preparing to support a purge of factions vocally supportive of his predecessor Jeremy Corbyn’s leadership.

Supporters of the former leader have claimed Starmer has rolled back moves to democratise the party and that he has fought some of his own members with more gusto than the Tories.

On Twitter, 85-year-old Loach, a winner of the Palme d’Or for I, Daniel Blake, said: “Labour HQ finally decided I’m not fit to be a member of their party, as I will not disown those already expelled. Well … I am proud to stand with the good friends and comrades victimised by the purge. There is indeed a witch-hunt … Starmer and his clique will never lead a party of the people. We are many, they are few. Solidarity.”

Loach previously left the Labour party in the 1990s, reportedly in disgust at Tony Blair, after three decades as a member. He has also been active in political parties such as Respect and Left Unity that have presented themselves as a radical alternative to Labour. He rejoined the party following Corbyn’s election to the leadership.

The former shadow chancellor John McDonnell tweeted: “To expel such a fine socialist who has done so much to further the cause of socialism is a disgrace. Ken’s films have exposed the inequalities in our society, have given us hope for change & inspired us to fight back. I send my solidarity to my friend and comrade.”

Corbyn was suspended from the party in October last year for saying the problem of antisemitism within Labour was “dramatically overstated for political reasons” by opponents and the media. A disciplinary panel of the NEC lifted the suspension the following month after he issued a conciliatory statement but Starmer refused to restore the whip to Corbyn.

Howard Beckett, a member of the NEC, was suspended from the party in May after he called for the home secretary, Priti Patel, to be deported on Twitter.

A Labour spokesperson said: “We are not going to comment on individual cases. As previously reported, the NEC took the decision to proscribe a number of organisations at its last meeting.”