The Northern Ireland secretary has insisted that plans to override the Northern Ireland Protocol are within the law - but critics say the move is "disgraceful".
Brandon Lewis defended the proposals as the government prepares to publish legislation on Monday despite growing concern about the legalities of the move.
One senior Tory MP has told Sky News the bill will include "notwithstanding clauses" regarding the Withdrawal Agreement, "a clear breach of international law".
Mr Lewis, speaking on Sophy Ridge on Sunday, reiterated the government's position that Brussels is refusing to be flexible in renegotiating the protocol - which governs Northern Ireland's post-Brexit trading arrangements.
He said the legislation being tabled in the Commons sought to "fix the problems" with the way the deal was being implemented.
"What we're going to do is lawful and is correct," he said.
But there have been questions about the extent to which top government adviser Sir James Eadie QC was consulted on the legislation being proposed.
Sir James, the first treasury counsel, has already revealed that he was not asked to give his legal opinion on whether it breaks the law.
Mr Lewis said he would "not get into the internals of government advice".
But he told Sky News: "The government lawyers were very clear. We are working within the law."
He said the attorney general would be setting out the government's legal position on Monday.
Speaking on the same programme, Sinn Fein president Mary Lou McDonald said Mr Lewis was "talking through his hat".
She insisted that the protocol is working and that the government's plans would result in "untold economic damage".
"It is disgraceful to use the north of Ireland as a bargaining chip in their ongoing collision with Europe, all designed to boost the ego, the leadership ambitions, of either Boris Johnson or one of his would-be successors," Ms McDonald said.
Labour's shadow chancellor Rachel Reeves told Sky News: "It does look like the government plans to break international law.
"This government seems to be developing a record for lawbreaking and it is not one that the Labour Party can support."
The Northern Ireland Protocol was the compromise between Boris Johnson and the European Union, avoiding a hard border between Northern Ireland and the Republic after Brexit.
Northern Ireland remains under some EU rules and there are checks on goods entering Northern Ireland from Great Britain, effectively creating an Irish Sea border.
Some claim the protocol is causing difficulty for businesses but others suggest having unique access to both the UK and EU markets is benefitting them.
Hardline Brexiteers say it undermines Northern Ireland's place in the UK and the Democratic Unionists have refused to enter power-sharing until the issue is addressed.
The senior Tory MP who spoke to Sky News also claimed the draft bill would not allow for disapplication, even if the Northern Ireland Assembly gives backing to the protocol.
"This is pretty nuclear and will become a major focus. The Irish government and the Americans will go nuts when this is published," he said.
Under the terms of the agreement, the Stormont Assembly is entitled to vote in 2024 on whether to keep or drop the Northern Ireland Protocol.
"If the draft Bill overrides the consent vote, it is because the government didn't like the results of the recent Stormont election," the MP added.