Parliamentarians from the ruling British Conservative Party strongly criticized U.S. Democratic presidential candidate Joe Biden after the 77-year-old politician said he would not approve a U.S.-British free trade agreement under the current measures proposed by London.

Through his Twitter account, Biden had spoken out against Prime Minister Boris Johnson’s proposal to amend part of the European Union’s 2019 Withdrawal Agreement.

Although, according to the Daily Mail, the Internal Market Bill, currently being discussed in the House of Commons, would allow the government to undo sections related to the status of Northern Ireland, Johnson’s government has already clarified on several occasions that it is not its intention to affect the Good Friday Agreement and that it will seek to reach a common agreement with Belfast.

The Good Friday Agreement (also known as the Belfast Agreement) was signed in 1998 by the British and Irish governments and ended the Northern Ireland Conflict, which had been going on for almost three decades.

Biden’s comments came Wednesday when Foreign Secretary Dominic Raab was in Washington to meet with politicians, especially from the Democratic Party, who were threatening to block a U.K.-U.S. trade agreement.

The agreement needs to be ratified by Congress, and the Democrats, who have a majority in the House, have already threatened to stop its progress.

Before meeting with House Speaker Nancy Pelosi (D-Calif.), Raab had made it clear that the UK is “absolutely” committed to the Good Friday Agreement.

Likewise, despite the doubts cast by the Democratic opposition, a Johnson spokesman again assured: “The PM has been clear throughout that we are taking these steps to precisely make sure that the Belfast Agreement is upheld in all circumstances and any harmful defaults do not inadvertently come into play.”

“We will continue to engage with our U.S. partners to ensure that our position is understood,” the spokesman said.

Hours later, however, Biden noted on social media that if enacted, the British government’s bill would threaten the U.S.-U.K. trade agreement.

“We can’t allow the Good Friday Agreement that brought peace to Northern Ireland to become a casualty of Brexit. Any trade deal between the U.S. and U.K. must be contingent upon respect for the agreement and preventing the return of a hard border,” Biden said.

Biden’s comments provoked a strong reaction in the British conservative ranks.

“We don’t need conferences on Mr. Biden’s Northern Ireland peace agreement,” said former Tory leader Iain Duncan Smith.

“‘If I were him I would worry more about the need for a peace deal in the USA to stop the killing and rioting before lecturing other sovereign nations,” the British politician told the Times.

Likewise, Joy Morrissey, an American-born British Conservative Party politician accused the Democrat of persecuting the “Irish-American vote” before the November elections.

Unlike Biden and the Democrats, U.S. Secretary of State Mike Pompeo supported the Downing Street initiative.

“Yes we trust the United Kingdom. I am confident they will get it right,” Pompeo said at a press conference.