The leader of Sinn Fein, the Irish nationalist party, accused the UK Prime Minister on Sunday of sacrificing Northern Ireland to strengthen his own weak position.

Johnson's government is expected to introduce a new law on Monday to adjust its post-Brexit commitments vis-a-vis Northern Ireland, denying at the same time that he was breaking the treaty obligations toward the EU, according to AFP.

Brandon Lewis, the Secretary of Northern Ireland, said the bill was "lawful" and necessary in order to mend problems in the EU protocol and restore a power-sharing government in the territory.

Sinn Fein's all-Ireland president, Mary Lou McDonald, said that the bill would break the EU withdrawal treaty, and referred to Johnson's narrow escape in the vote that took place last Monday.

"It is disgraceful to use the north of Ireland, to use Ireland, as a bargaining chip," she told Sky News, accusing the Tories of "games and gamesmanship".

These proposals, according to McDonald, are designed to boost the "ego" and "leadership ambitions" of Johnson or one of his would-be successors.

"It's dishonourable stuff, by any measure extraordinary stuff."

Northern Ireland's Secretary said that the Northern Ireland protocol was disrupting trade and lacked support from the region's pro-UK unionist parties.

"So it's right that we repair that," he said, while also pointing out that the need to protect a 1998 peace agreement in Northern Ireland had "primacy" over the protocol, which the Democratic Unionist Party is jeopardizing the territory's status in the UK.

McDonald, on the other hand, accused the UK government of "undermining, attacking and damaging" the 1998 agreement.

The protocol requires checks on goods arriving from England, Scotland and Wales, to prevent them from entering the EU market via the Republic of Ireland. The UK bill, however, will do away with most of these checks, and create a channel for British traders to send goods to Northern Ireland without making customs declaration to the EU.