Alastair Campbell has been kicked out of the Labour Party for voting Liberal Democrat at the European elections.
Tony Blair’s former communications director backed the rival party over its support for a second Brexit referendum, he revealed during an interview on LBC on Sunday.
Labour emailed Campbell on Tuesday to tell him that his actions were “incompatible with party membership”.
Campbell, who has been a long-standing advocate for a so-called people’s vote on EU membership, tweeted that he was “sad and disappointed” by the news – and that he may launch a legal challenge.
Labour has faced an avalanche of criticism from its pro-EU membership over its Brexit policy.
Jeremy Corbyn’s position has been to push for a general election while keeping a second Brexit referendum as “an option on the table”.
The news provoked strong criticism from Labour MPs, including Wes Streeting and Jess Phillips, who said the party expelled Campbell within two days but had failed to promptly expel members over anti-Semitism - something which the party has been repeatedly accused of but Labour strongly denies.
It came as the Equality and Human Rights Commission (EHRC) confirmed it would investigated the party over whether it “unlawfully discriminated against, harassed or victimised people because they are Jewish”.
Since the party suffered heavy losses to Vince Cable’s party at the European parliament poll, leading party figures have indicated Brexit policy may shift.
A Labour spokesman said: “Support for another political party or candidate is incompatible with Party membership.
“The Lib Dems cannot and will not end austerity. They cannot bring our country together or be trusted to deliver on their promises. They propped up the Tories for five years and imposed the austerity that has devastated our communities.
“Labour will do things very differently, and ensure our society is run for the benefit of the many, not just a privileged few.”