The head of the British government's legal department, Jonathan Jones, has quit over suggestions that Prime Minister Boris Johnson is threatening to override the UK's Brexit deal with the European Union, according to the Financial Times.
According to reports, Jones is leaving amid the prime minister's reported plans to challenge the Withdrawal Agreement treaty, which was signed in January, in relation to Northern Ireland.
Boris Johnson said on Friday that the United Kingdom is prepared for any eventuality from the ongoing post-Brexit negotiations with the European Union over the Free Trade Agreement (FTA).
Under the current deal, the UK government has agreed to certain checks being in place post-2020 on some goods entering Northern Irish ports from the rest of the UK, although no tariffs are expected to be levied on produce remaining within the UK's unified customs territory.
According to the document, entitled "The UK's Approach to the Northern Ireland Protocol", tariffs will be levied "on goods at risk of entering the EU’s Single Market at ports of entry" in a bid to avoid the construction of customs infrastructure at the land border between the Republic of Ireland and Northern Ireland.
Border posts and checkpoints between Northern Ireland and the Republic of Ireland were removed after the 1998 signing of the Good Friday Agreement, which brought three decades of violence between Irish republicans and unionists loyal to the United Kingdom to an end.
The possibility of a no-deal Brexit is looming as both sides have blamed each other for the lack of progress in trade talks.
The UK withdrew from the EU on 31 January. The two have agreed to a transition period until 31 December to negotiate bilateral trade terms. The key issues they disagree on are regulations on fisheries and state aid.