A former chief whip under Tony Blair has said she was “very sad” after her local constituency party voted to expel her from the Labour party.

Hilary Armstrong issued a statement after a meeting of the North West Durham constituency party, where she was MP until 2010, after the decision, which came days after she added her name to an advertisement accusing Jeremy Corbyn of having “failed the test of leadership” over his handling of antisemitism complaints within Labour.

The Labour peer said her local constituency “used to be a place where differing opinions were respected”.

Armstrong said: “This sadly shows how far the party has departed from its roots. I’m not going to shy away from demanding that the party leadership take real and decisive action to rid antisemitism from the Labour party.”

The full-page advert, published in the Guardian on Wednesday, criticised Corbyn for allowing a toxic culture to “divide our movement”. It said the party was no longer a safe place for its members and supporters.

News of the Armstrong vote prompted outrage from Labour colleagues in the north-east, with the Redcar Labour MP Anna Turley tweeting: “If this is true it is disgraceful.”

Turley added: “Hilary has served the Labour party with commitment and distinction for decades, as a former social worker, particularly for the vulnerable. She is Labour to her marrow and if there is no place for her in it, it is done.”

The Sunderland Central MP, Julie Elliott, said the vote to remove Armstrong, chief whip under Blair from 2001 to 2006, was “astonishing”.

She said: “Hilary Armstrong has done more for the Labour party than anyone I know, supported women to become active and get elected – she is Labour to her core has true Labour values I am proud to call her a friend – words fail me.”

Pat Glass, Armstrong’s Labour successor in North West Durham, tweeted: “She has broken no rules unless free speech is now banned in the UK Labour [party].”

The advert, supported by 67 Labour members of the House of Lords, including former cabinet ministers Peter Hain and Peter Mandelson, followed a damning report by the BBC’s Panorama programme into the party’s handling of allegations of antisemitism.