Jacob Rees-Mogg warned Sir Keir Starmer is trying to return Britain to the EU “via the back door”.

The Prime Minister said at the Interpol general assembly in Glasgow yesterday that he wants to restore pre-Brexit intelligence-sharing arrangements with the EU to help tackle people smugglers.

But former Tory MP Sir Jacob warned Labour wants to undo Brexit “bit by bit”.

Speaking on his GB News show, he said: “It was said occasionally by Brexiteers during the referendum campaign, though not nearly enough, that the EU was becoming the United States of Europe.

“When Nigel Farage raised the concerns of the European army it was dismissed by then Deputy Prime Minister Nick Clegg as ‘a dangerous fantasy’.

“It was, of course, a policy officially endorsed as an aspiration by Emmanuel Macron, the president of France, and Angela Merkel, the former chancellor of Germany.

“What Remainers never really wanted to admit to the public, possibly because they didn’t really like the idea anyway, was that the European project wanted to go on to move Europe from being a coalition of nations to being a single state.

“Well, Sir Keir Starmer, also famous for wanting a second referendum, now appears to be keen to drag us back into one of the EU’s key federalist policies – Europe’s justice and home affairs wing – under the guise of smashing the gangs.

“At the Interpol meeting yesterday in Glasgow, he claimed that Brexit had meant the UK no longer had access to the European Arrest Warrant database, and that he wanted this restored.

“But be under no illusion, any restoration of the pre-Brexit settlement will come at a cost, in this case almost certainly our return to European Arrest Warrant.

“But this system not only gives jurisdiction to European judges in the UK, as it would be ruled on by the Court of Justice of the EU, but it would treat the UK as a state within their Federation rather than the position we have restored; that of a sovereign nation.

“The Prime Minister is meeting European leaders on Thursday in Hungary and the new EU security pact is expected to be at the top of his agenda.

“But this is merely the first step in dragging us back to the EU via the back door. Keir Starmer has always wanted to be in the EU.

“He didn’t want to leave, he wanted a second referendum and now, bit by bit, they’re trying to get us in.

“It’s like a frog in water, the water is gradually warming up. But we’re alert, we’re not going to be frog-like and be gently boiled.”

It comes as the PM is set to push for a new security deal with Brussels when he meets fellow leaders at the European Political Community summit in Hungary on Thursday.