The European Union appears set to agree to a delay on Britain's exit from the bloc, but officials in Brussels are anxious about the impact that might have on European parliamentary elections in May.
They fear a wave of Euro-skeptics will be returned by British voters, if the country participates in the elections, reinforcing an expected strong populist showing across the continent.
Some EU officials are already exploring legal ways to try to stop British participation on the grounds that the country may not be a member by the time the parliamentary term expires. Instead they want either the current British MEPs (Members of the European Parliament) to continue in place or for the British government to appoint temporary Euro-lawmakers reflecting the current party strengths in Britain's House of Commons.
But Brexiters are already exploring legal action to block any attempts to prevent British participation. Leading Brexiter Nigel Farage says a new party he's launched plans to field a full slate of candidates. Lawyers acting for the hardline Brexit campaigning group, Leave Means Leave, are in talks with Downing Street.
John Longworth, chairman of the group, which favors a "no-nonsense" Brexit, departing without any deal, said in a statement: "We are determined to challenge the government and EU if they attempt to deny the democratic right of the people of the UK to be represented in the EU Parliament."
On Thursday, Prime Minister Theresa May is due to meet European national leaders in Brussels, where she will request a Brexit extension following the parliamentary rebuff of her EU withdrawal deal, which was agreed with Brussels last November. The House of Commons has also blocked Britain exiting the EU without a deal.
It is unclear whether she will ask for a short three-month extension, hoping still to secure parliamentary approval for her deal that has been rejected twice now, or for a longer postponement. France and Germany favor a longer extension of 21 months.
Prime Minister May has warned Brexiters opposed to her deal, which she might put to a parliamentary vote again Tuesday, that they will have to take part in the Euro-elections, if they vote again against her EU divorce agreement and it is delayed beyond June 30, shortly before new MEPs take their seats.
The Brexit mess is becoming as much a legal nightmare as a political one for both Britain and the EU. On Monday the Speaker of the House of Commons ruled under parliamentary rules that Prime Minister Theresa May can’t bring back her Brexit deal for a third for a vote after it has been rejected twice before.
In Europe, one legal opinion offered to EU ambassadors last week warned that Brussels would be obliged under the bloc's rules to terminate British membership of the EU on July 1, if Britain has not participated in the May 23 Euro-elections.
"No extension should be granted beyond 1 July unless the European parliament elections are held at the mandatory date," the legal opinion stated.
For EU officials and centrist European politicians, who had always hoped Brexit would be reversed, the prospect of British participation in the May elections might be a case of be careful for what you wish for.
"We could see a lot more people like Farage elected to the parliament," said a senior EU official. "And that risks emboldening populists across the bloc and upsetting efforts to try to restore stability and predictability in the face of rising nativism," he added.
On Monday, British trade minister Liam Fox warned the ruling Conservatives that they "need to be ready to take part in the European elections in May."
This year's European parliamentary elections are likely to be the most important the bloc has ever held. Two conflicting visions of Europe are on offer with centrists led by French President Emmanuel Macron and nationalist populists championed by Italy's Matteo Salvini struggling for mastery. The populists have turned for advice to former Donald Trump aide Steve Bannon.
Macron has pitched himself as the antidote to the "illiberal democracies" of Central Europe and the defender of the European Union threatened by populist-nationalists like Salvini. The French leader wants to reform and revive the bloc by deepening political and economic integration of Europe.
The 44-year-old Salvini wants the opposite, not only a brake on further integration, but a reversal with the bloc consisting of a looser grouping of nation states less hedged by Brussels and EU treaties.
In their campaigning the populists are exploiting what French historian Jean Garrigues, a critic of the populists, recently described as the "EU's original sin" — building an "economic Europe" that is too technocratic as the first step in building European political unity. This has resulted in a deficit of democracy and trust and "led to a governance by a very technocratic commission which has become an ideal scapegoat," he said.
Populist parties, especially in Italy, Poland, Hungary and France, expect to make major gains in the May elections and are coordinating their campaigning. In France, opinion polls suggest that Marine Le Pen's Rassemblement National is now neck-and-neck with Macron's En Marche party. Salvini's Lega party has performed strongly in recent regional elections. Germany's hard-right Alternative fur Deutschland, the largest opposition party in the country, is also likely to pick up seats.
Pollsters are predicting Euro-skeptics will capture a third of the European parliament's 705 seats.