LONDON, Oct. 9 (Xinhua) -- A question mark hung over Brexit Tuesday after a war of cross-channel words appeared to put a deal between Britain and Brussels in doubt.

The growing prospect of both sides failing to reach a deal over Britain's departure from the European Union sent the value of the pound against the U.S. dollar and the euro dropping on the money markets.

Political commentators went into overdrive after an early morning telephone call between British Prime Minister Boris Johnson and German Chancellor Angela Merkel.

The prime minister's official spokesman said the conversation had been "frank" but denied the negotiations were all but over.

Under Johnson's proposals, Northern Ireland would remain allied to the single market to enable trade to continue with the Republic of Ireland without the need to create border posts on the island of Ireland.

In Berlin, a spokesperson for the German government confirmed there had been a conversation between Merkel and Johnson.

Donald Tusk, president of the European Council, posted a message on his public social media pages aimed directly at Johnson: "What's at stake is not winning some stupid blame game. At stake is the future of Europe and the UK as well as the security and interests of our people. You don't want a deal, you don't want an extension, you don't want to revoke, quo vadis?

In London, the Guardian newspaper reported that talks over a Brexit deal are on the brink of collapse over claims Merkel was making a deal impossible.

Most of Britain's other national newspapers, including the Times and the Guardian, said a Brexit deal was near collapse.

"Boris Johnson's Brexit deal appears doomed as deadline looms," headlined the Guardian.

The Times said it came after Merkel insisted that Northern Ireland should stay in the EU Customs Union.

The Daily Telegraph also headlined the Brexit collapse story, with the Independent saying Brexit talks were on the brink.

In the House of Commons, Cabinet Minister Michael Gove responded to the day's developments, telling MPs that while a no-deal Brexit is not his preferred outcome it is possible.

"It is of course possible for a host of reasons that we might leave on October 31 without a deal," he said.

Keir Starmer, Brexit spokesman for the main opposition Labour Party, described the reported suggestions that Brexit negotiation talks have stalled as 'sabotage' by Number 10.

"It is now more important than ever that parliament unites to prevent this reckless government crashing us out of the EU at the end of the month," he added.

In Belfast, Arlene Foster, leader of the Democratic Unionist Party, described a suggestion that Northern Ireland would be kept in the EU Customs Union as beyond crazy.

Earlier, the British government released its no-deal readiness report showing the UK is confident it can leave without a deal. In the report, Johnson declares he can say with confidence that Britain is prepared to leave the EU on Oct. 31 without a deal.

Meanwhile, at the Court of Buckingham Palace, Queen Elizabeth II signed an order suspending the British parliament at the end of Tuesday's business. The monarch will conduct a state opening of a new session of parliament next Monday.

A hectic day of Brexit uncertainty drew to a close with Johnson Tuesday night meeting President of the European Parliament David Sassoli in Downing Street.

After Johnson met the president on the steps of Number 10, one journalist shouted: "Is there any point in still talking?"

Johnson, who had waved at the media group, shouted back: "Of course." The Guardian reported late Tuesday that Sassoli had emerged from the Downing Street meeting looking downbeat.

He told waiting reporters: "I sincerely hope there will be a wake-up call. Up to the very last minute it will be possible for the European Union and the (British) parliament to try and find a deal."

On Oct. 17, Johnson is scheduled to travel to Brussels for a meeting of the European Council where he hopes a Brexit deal could be ratified.

Political commentators now say they expect Britain to extend its membership of the EU, with an early snap general election.