Demonstrators in support of the European Union outside the Cabinet Office in London on Friday (NYT)

LONDON: UK Prime Minister Boris Johnson 's Brexit plan was facing mounting legal, political and diplomatic challenges on Friday as Ireland accused Britain of being unreasonable and former British leader John Major sought to stop the suspension of parliament.

Johnson, the face of the Vote Leave campaign in the 2016 referendum, has promised to lead the UK out of the European Union in two months with or without a divorce deal, a threat he hopes will convince the bloc to give him the exit deal he wants.

The PM warned on Friday that opposition to his plans is weakening Britain's negotiating position by giving EU leaders the impression that parliament may step in to block Brexit. "I'm afraid that the more our friends and partners think, at the back of their mind, that Brexit could be stopped, that the UK could be kept in by parliament, the less likely they are to give us the deal that we need," said Johnson. He claimed there is still time to make a deal with the EU.

Johnson's bid to get the insurance policy for the Irish border changed were bluntly dismissed by Dublin which said London was being totally unreasonable. "Boris Johnson is outlining a very clear and firm position but it is a totally unreasonable position that the EU cannot facilitate and he must know that," Irish foreign minister Simon Coveney said in an interview with Ireland's Newstalk radio.

German foreign minister Heiko Maas said Britain should make concrete proposals as soon as possible but that the EU could not imagine reopening the Withdrawal Agreement that Theresa May agreed with Brussels in November. Britain insisted it had made proposals on the border backstop and that it was "untrue" to suggest it had not.

There are three ongoing court tests to Johnson's plan, which he says is routine but which will shorten the time in which opponents in parliament could seek to pass legislation blocking a disorderly "no deal" departure from the European Union.

A Scottish judge on Friday declined to issue an immediate injunction to block the suspension of parliament but set up a full hearing on Tuesday on the legal bid launched by cross-party legislators determined to keep parliament in session. A separate case in London has also received the heavyweight backing of former PM John Major - a fellow Conservative from Johnson's party - and from Tom Watson, the deputy leader of the opposition Labour Party.

"If granted permission to intervene, I intend to seek to assist the court from the perspective of having served in government as a minister and prime minister, and also in parliament for many years as a member of the House of Commons," he said.

A case is being heard in Northern Ireland, as well. The various courts are being asked to intervene in what is seen by Boris Johnson's opponents as a power grab that undercuts the sovereignty of parliament .

Organisers say more than 30 protests have been planned in cities throughout the United Kingdom. Activists hope a massive turnout could influence vacillating members of parliament when it reconvenes on Tuesday after a summer recess.

In Scotland, Judge Raymond Doherty turned down a bid for an immediate intervention but said a "substantive" hearing on Tuesday would allow the case to be heard in a timely fashion. He did agree to move the full hearing from September 6 to Tuesday to speed up the process. The case was brought by a cross-party group of roughly 70 legislators seeking to broaden the period for parliamentary debate in a bid to prevent a disorderly departure by Britain from the European Union.

The legislators backing the legal bid want Johnson to submit a sworn affidavit explaining his reasons for suspending parliament. It is not clear if such a statement will be required. Agencies

