Boris Johnson has refused to say if he would back Rishi Sunak's Brexit plans - and insisted his law-breaking bill was better.
The disgraced former Prime Minister twice declined to declare his support for Mr Sunak's efforts to renegotiate a key part of the Brexit deal governing Northern Ireland.
Instead, Mr Johnson claimed that the "best way forward" was to press on with controversial legislation he tried to force through Parliament to allow the UK to rip apart the deal he signed without EU consent.
Mr Sunak has put the divisive Northern Ireland Protocol bill on ice while he tries to strike a new deal with Brussels to ease trading issues caused by the original deal.
The bill infuriated the EU and some Tory politicians, who think it breaks international law and undermines the UK's global reputation.
Speculation has been mounting for days that the Prime Minister has agreed new terms with the EU - but No10 has refused to give any details.
Tory right-wingers and the hard-line Democratic Unionist Party (DUP) are said to be unhappy, in gloomy echoes of the Brexit battles of the past.
Mr Johnson has been lurking in the background making his feelings clear about any attempts to sell out what he regards as a key part of his No10 legacy.
Tensions also remain between the ex-PM and Mr Sunak. Mr Johnson's allies blame Mr Sunak for his downfall after he resigned as Chancellor amid a mass revolt against Mr Johnson's leadership.
Asked if he'd support the plans, Mr Johnson said: "I think that it is important to wait to see what there may be but I think the best way forward, as I said when I was running the Government, is the Northern Ireland Bill, which cleared the Commons very comfortably, I think unamended, when I was in office and only a few months ago.
"So, I think that is the best way forward."
Pressed again, he said: "I think the best thing is to continue with the Northern Ireland Bill that we agreed.
"It is a very good Bill, it fixes all the problems, it solves the problems we have in the Irish Sea, it solves the problems of paperwork, VAT and so on.
"It is an excellent Bill and doesn't set up any other problems in the economy of the whole island of Ireland. So, I'd go with that one."
The Northern Ireland Protocol effectively keeps it in the EU's single market for goods, meaning checks on products crossing from Great Britain.
It was designed to prevent a border between Northern Ireland - which left the EU along with the rest of the UK - and the Republic of Ireland - which remains in the bloc.
But businesses have complained about extra red tape and the situation led to the collapse of powersharing at Stormont following anger from the unionist DUP party.
No deadline has been set for resolving the problems with the protocol but the looming 25th anniversary of the Good Friday Agreement in April is seen as critical.
