Sir Keir Starmer has denied changing his position on whether the government has to give MPs a vote on any plans by the UK to take military action.
The Labour leader backed the US-UK air strikes in Yemen, launched without a parliamentary vote.
He told the BBC on Sunday a vote was only needed when “deploying troops”.
During his leadership campaign Sir Keir had pledged to create a law requiring “the consent of the Commons” for military action.
Speaking on Laura Kuenssberg on Sunday, Sir Keir said action had to be taken on Houthi targets because “sitting back and doing nothing” would not have been appropriate.
He had been briefed shortly before the operation, and he said the government must make a statement in the Commons on Monday, as is planned.
If there were further plans for action in Yemen, he would expect to be given a similar briefing and that Labour would consider this “on its merits”.
Four years ago, when campaigning to be leader, Sir Keir said he wanted a new law “that said military action could be taken if first the lawful case for it was made, secondly there was a viable objective and thirdly you got the consent of the Commons”.
Sir Keir insisted there was “no inconsistency” between his previous comments and his support for the air strikes in Yemen, telling the programme that there is a difference between this action on Houthi targets and “sustained” military action.
Separately pressed on whether he had changed commitment to stop the UK selling weapons to Saudi Arabia, Sir Keir said he supported a review into all UK arms sales which will “make clear” what Labour’s position is.
The Labour leader argued his party is different now from the one he ran to lead in 2020.
Reports that four people have died in an attempt to cross the English Channel are a “tragic loss of life”, Sir Keir said.
The Labour leader said the deaths show “we need to stop these Channel crossings”.
“Now I think the starting place for that is to go after the criminal gangs that are running this vile trade,” he added.