Tobias Ellwood, chair of the Commons’ defence select committee, has had the UK Conservative party whip removed after failing to support the government in Monday’s confidence vote.

Ellwood, who served as junior defence minister under Theresa May’s government, has been critical of Boris Johnson and was one of the first MPs to call for the prime minister to quit.

He abstained in Monday’s confidence vote against the government, which Johnson won with a majority of 111. The vote was tabled by the government after a dispute with Labour’s initial request.

The office of Chris Heaton-Harris, chief whip, said Ellwood had lost the whip “following his failure to vote in support of the government in the confidence vote last night”.

One senior Tory said that Ellwood had requested a “slip” to not be present for the confidence vote to undertake a foreign trip, but all such requests had been rescinded.

In response to losing the whip, Ellwood said: “Following my meeting yesterday with the president of Moldova, I was unable to secure return travel due to unprecedented disruption both here and in the UK.

“I am very sorry to lose the whip but will now continue my meetings in Ukraine promoting the prime minister’s efforts here and specifically seeking to secure the reopening of Odesa port — so vital grain exports can recommence.”

The suspension of Ellwood’s whip means one MP fewer voting in the latest shortlisting round of the leadership contest.