A Jeremy Corbyn ally who has campaigned for the deselection of MPs disloyal to the Labour leader has vowed to fight any attempts to remove him from his constituency.

Chris Williamson, the MP for Derby North, said he would welcome a trigger ballot following reports that he is facing a possible contest.

The Huffington Post reported that several sources said Williamson will “definitely” be challenged under new party rules that have made it easier to oust sitting MPs.

The changes mean one-third of union branches are needed to force a contest.

Asked about the report, Williamson said: “I’d welcome a selection contest if one is triggered. I am continuing to campaign for open selections in every constituency.”

On whether he knew of a campaign to oust him, he said: “No more than anyone else with the new trigger ballot system.”

Until last month, more than 50% of local branches including unions had to support any challenge. Now, only 33% have to back any such move.

Williamson, who is a supporter of the grassroots Momentum organisation, has run a Democracy Roadshow campaign for the mandatory reselection of every sitting Labour MP.

He disagreed with the Unite and GMB unions at the Labour conference last month, after they blocked an attempt to open up every parliamentary seat to automatic selection.

Union officials claimed the rule change would have cut them out of the process and transferred power and influence to party members.

Williamson reportedly argued with the Unite general secretary, Len McCluskey, at the conference in Liverpool, over a Morning Star newspaper article that claimed Unite had abandoned its previous support for mandatory reselection. Williamson insisted their exchange was a conversation.

The following day, McCluskey accused Williamson of undermining Corbyn by splitting socialists in the Labour movement.

A union source said there was “real anger” towards Williamson in Derby and this would result in an attempt to initiate a trigger ballot.

“He is his own worst enemy. He doesn’t know when to stop,” the source said.

Williamson won Derby North back from the Tories in 2017, having lost the seat in 2015. He has a majority of 2,000.

Labour lost control of the council to the Conservatives this year. Some local activists have claimed Williamson should have spent more time campaigning in Derby instead of touring the country.