LONDON, Oct. 15 (Xinhua) - Britain's post-Brexit relationship with the European Union entered its most critical week Monday with London and Brussels still unclear about the outcome.

The fate of Brexit, as well as the future of Prime Minister Theresa May, dominated British media Monday, as pro-EU and Euro skeptics sharpened their knives for a war of words that could either spell disaster or rescue May's proposals for a future relationship deal.   

The Guardian newspaper described the Brexit negotiations as being on a knife-edge, with all eyes focused on a crucial meeting Tuesday of May's cabinet at 10 Downing Street.    

The Independent newspaper said May's leadership as well as her plans for Brexit are under pressure.

The big stumbling block is how to resolve the seemingly impossible question of the post-Brexit border between British-controlled Northern Ireland, and the Irish Republic which will remain as an EU member.

The 500-km border between the two will become the only border within the British Isles between the EU and the UK after Brexit    

Currently, as part of a hard-won peace settlement that brought to an end decades of troubles in Northern Ireland, there are no borders on the island or Ireland. 

Hopes of a breakthrough at a hastily called meeting Sunday between Britain's Brexit Secretary Dominic Raab and EU Brexit negotiator Michel Barnier were dashed, with the Irish problem unresolved.   

A joint statement issued by 10 Downing Street and the Department for Exiting the EU said a number of unresolved issues remained following Sunday's talks between Raab and Barnier but the UK was "still committed to making progress" at Wednesday's summit of all EU member state leaders.   

Ahead of Wednesday's summit, May faces what could be one of the most critical cabinet meetings of her tenure in Downing Street.   

With talks of a rebellion by some of her most senior ministers, May will learn this week whether she has enough support among her ministerial team, or faces a crisis if there is a string of resignations.

To add to May's woes, the leader of the Democratic Unionist Party (DUP), Arlene Foster, has insisted her party will not support a deal that sees Northern Ireland and mainland Britain treated differently.

May relies on the 10-strong contingent of DUP MPs at Westminster to shore up her minority government.

Former foreign secretary Boris Johnson, who resigned over his opposition to May's Brexit proposals, said Monday it was time for Britain to stand up to EU bullies.

Writing in the Daily Telegraph, Johnson said; "There comes a point when you have to stand up to bullies. After more than two years of being ruthlessly pushed around by the EU, it is time for the UK to resist."

He added: "We are now entering the moment of crisis. Matters cannot go on as they are. The EU is treating us with naked contempt. Like some chess player triumphantly forking our king and our queen, the EU Commission is offering the UK government what appears to be a binary choice. It is a choice between the break-up of this country, or the subjugation of this country, between separation or submission. It is between treating Northern Ireland as an economic colony of the EU, or treating the whole of the UK as such a colony. It is a choice between protecting the Union or saving Brexit."

The Independent said Monday that former Brexit secretary David Davis, who also quit at the same time as Boris Johnson, has told Conservative MPs they should trigger a leadership contest to topple May unless she drops her Brexit plan this week.

Davis wants the prime minister to be presented with an ultimatum that her party will seek to remove her if she refuses to budge before Wednesday's crunch EU summit, the Independent reported.

Meanwhile, across the Irish Sea, the Belfast News Letter reported Monday that the DUP's Brexit spokesman Sammy Wilson said Britain's departure from the EU without a deal is "probably inevitable".

Wilson told the newspaper: "Given the way in which the EU has behaved and the corner they've put Theresa May into, there's no deal which I can see at present which will command a majority in the House of Commons. It is probably inevitable that we will end up with a no deal scenario."