Ministers have been accused of allowing plans to curb illegal crossings to “completely unravel" as it emerged the Navy was to axe its role in patrolling the Channel.
The Ministry of Defence has reportedly told ministers that it will pull out of its responsibility for dealing with migrant crossings in January next year.
Defence Secretary Ben Wallace denied this was a "new announcement”, noting a previous statement had said the arrangement had been agreed until January 31.
And a Ministry of Defence spokesperson said the plan would be “reviewed” in the new year.
But Yvette Cooper, Labour's Shadow Home Secretary said: "Yet another Conservative policy on channel crossings has completely unravelled while the number of lives put at risk in dangerous crossings is still rising.”
Foreign Secretary Liz Truss said the Navy would “absolutely” maintain the military presence if she won the race to replace Boris Johnson as PM.
She said: “It is an absolute priority to make sure we deal with the issue of small boats and the appalling trade by people traffickers," she said in Elgin, north east of Inverness.
"And I will use every tool at my disposal, if I am selected as prime minister, to make that happen."
Ms Cooper added: “Conservative Ministers have repeatedly chased headlines rather than doing the hard work to tackle the problem.
“The Navy was pulled into this because Home Office Ministers were already failing and this comes on top of damning reports into failings in the Home Office management of Border Force, as well as hundreds of millions of pounds wasted on the unworkable Rwanda scheme."