BRUSSELS (Reuters) - Theresa May told fellow European Union leaders that she was taking emergency political measures not seen in Britain since World War Two as she urged them to give her more time to clinch a deal for an orderly Brexit.

British Prime Minister Theresa May leaves after holding a news conference following an extraordinary European Union leaders summit to discuss Brexit, in Brussels, Belgium April 11, 2019. REUTERS/Susana Vera? TPX IMAGES OF THE DAY

People present at Wednesday night’s crisis summit in Brussels said the prime minister appealed to her continental peers to appreciate the significance of her move to launch talks with her Labour opponents, saying the last united front between the two big parties in the fiercely tribal Westminster parliamentary system was when Britain faced a German “blitzkrieg” bombing campaign and invasion threat.

“She explained about the cross-party talks and made the point that, while such cross-party talks are a normal part of democratic life in most member states, it was not the case in the United Kingdom,” said one participant at the meeting.

“And that the last time there was some real cross-party cooperation was during the Second World War.”

Most of the other 27 members of the European Council either lead coalition governments or must deal with other power-sharing arrangements, while cooperation of any sort between Labour and May’s Conservatives in peacetime is vanishingly rare - although May was part of a Conservative coalition with the smaller Liberal party in 2010-15.

“WE’LL MEET AGAIN”

British sources said May had been aware in advance of a need to convince the EU that she had a new strategy for securing the parliamentary majority she needs to ratify an exit treaty she negotiated with Brussels, which British lawmakers have rejected.

In particular, she wanted to explain to veterans of Europe’s compromise-and-coalition politics that her move to open talks last week with Labour leader Jeremy Corbyn was a “significant undertaking” that held out a promise of finally securing a deal, if the EU extended the Brexit deadline beyond Friday.

Other leaders, who gave May an extension of up to six months to Oct. 31, said they had got the point.

Danish Prime Minister Lars Lokke Rasmussen, who leads a three-party minority coalition that is propped up by a fourth, came out of the meeting telling reporters that the delay to October was “to give a chance to the new thing that has happened in Britain -- where for the first time since World War Two they are having consultations across the political divide”.

Adding to the historical atmospherics, he underlined his belief that the EU leaders have not yet seen the end of the Brexit story by serenading journalists with a whistled version of the 1939 British song “We’ll Meet Again”, a tune that for Britons recalls wartime solidarity and the “spirit of the Blitz”.

“A SERIOUS COUNTRY”

EU officials and diplomats said the new October deadline was a compromise between French President Emmanuel Macron and most others, including Germany, which wanted a longer extension.

But the leaders were also not in fact greatly convinced May’s new plan would work.

For that reason, they were ready to give Britain longer to avoid a disorderly Brexit, aware that May could step down or be forced out, and that new elections or a second referendum on EU membership are all possibilities in the coming months.

One reason Macron gave for preferring to give May only until June 30, as she herself had asked, was his view that Britain under a hardline pro-Brexit successor could disrupt the Union if it stayed in. For that reason, the extension contained clauses obliging Britain to maintain “sincere cooperation” as a member.

May assured her peers that she accepted that, people present said, insisting that Britain did not want to leave in a way that would make it harder to maintain good relations in future.

She took a pointed dig at Conservative rivals, such as anti-EU campaigner Jacob Rees-Mogg, who say Britain could block and veto legislation to hobble the EU if it were not able to leave immediately, according to one participant in the summit.

“She also ... made the point that the United Kingdom was a serious country,” the source said, “and we should not get distracted by some non-members of the government who seem to be trying to create the opposite impression.”