Alastair Campbell has defended his decision to vote for the Lib Dems in the European elections after he was expelled from the Labour Party.
Tony Blair’s former spin doctor said he was voting tactically.
He said he would “always be Labour” but acted “in the best interests of what the Labour Party should be doing” by supporting a pro-Remain party.
Shadow minister Dawn Butler said members who admitted voting for another party were “automatically excluded”.
“It’s just part of the rule book. Everyone knows that,” she said.
Mr Campbell, a lead campaigner for another Brexit referendum, revealed he had voted Lib Dem during the BBC’s election night broadcast on Sunday.
Speaking to reporters after his expulsion, he said he believed other Labour MPs, councillors and peers voted in the same way as he did to try and make the leadership alter its position on Brexit.
The party lost ground in the European elections, and some figures have called for Jeremy Corbyn to unequivocally back another referendum to win back support, especially from Remainers.
“I don’t think I’ve left the Labour Party, and I’ll always be Labour. I suspect I will be in and around Labour longer than some of the people around Jeremy Corbyn at the moment”, he added.
He said he would appeal the decision.
In Twitter posts earlier, Mr Campbell claimed the decision also “contrasts with our era” when Mr Blair was “pressed” to withdraw the Labour whip from Jeremy Corbyn for voting against the party – but the then PM said no.
He also added that it was “hard not to point out difference in the way anti-Semitism cases have been handled” on the day the Equality and Human Rights Commission launched an investigation into allegation in the party.
Speaking after Mr Campbell’s expulsion, former Labour Defence Secretary Bob Ainsworth admitted he also voted for a different party last week.
He told BBC Coventry & Warwickshire: “Having recently voted Labour in local elections, I voted Green in the Euro elections having never voted other than Labour before in my entire life.
“I didn’t intend to make this public, but now Alastair has been expelled for doing the same I feel obliged to do so.”
Who is Alastair Campbell?
Mr Campbell was a political journalist before coming to prominence in Whitehall as a key member of the Labour PM’s staff in 1994.
He served as Mr Blair’s chief press secretary until 2000 and was a controversial figure, heavily involved in policy, including over the Iraq War.
Since leaving government, he has opened up about his struggles with depression and alcoholism, and works with a number of charities.
He also campaigns for the People’s Vote and is the editor of The New European magazine.
Labour MPs have taken to Twitter to criticise the move to expel Alastair Campbell.
Jess Phillips, who represents Birmingham Yardley, tweeted that Mr Campbell was “expelled quicker than a man who threatened to kill me [and] quicker than a man in my [local party] who denied the Holocaust”, adding: “Both are only still suspended.”
Barking MP and campaigner against anti-Semitism Margaret Hodge said the party’s “priorities are all wrong”,
And former Lord Chancellor in Mr Blair’s government, Lord Charles Falconer, said Mr Campbell was “Labour through and through”, adding: “Voting [Lib Dem] once in a lifetime on one issue should not lead to expulsion.”
But Labour activist and commentator Owen Jones questioned why there was “controversy” over his expulsion, adding: “The rule is, if you say you’re voting for another party, you auto exclude yourself.
“Those arguing this rule shouldn’t apply to Alastair Campbell do so because they agree with him and for no other reason.”
Last week, veteran Conservative and pro-European Lord Heseltine admitted he planned to vote Lib Dem in the election. The party responded by effectively expelling him.
Labour’s share of the vote fell to 14% in last week’s European elections and several senior figures have blamed a lack of clarity around Brexit.
The party agreed a policy at its last conference that if Parliament voted down the government’s withdrawal deal with the EU – which it has effectively done three times – or talks ended in no-deal, there should be a general election.
But if it could not force one, conference agreed that the party “must support all options remaining on the table, including campaigning for a public vote”.
Deputy leader Tom Watson said that nuanced stance had led to “electoral catastrophe”, while former PM Tony Blair said it was not “possible to sit on the fence on Europe and appeal to both sides”.
After the results, Mr Corbyn insisted his policy had been “very clear” all along – but sent a letter to his MPs, saying it was “clear that the deadlock in Parliament can now only be broken by the issue going back to the people through a general election or a public vote”.