Europe‘s leaders face a huge Brexit gamble on extending the UK departure

The 27 European countries are considering whether or not to grant the U.K. a long extension to its European exit, but this could be the bloc‘s biggest Brexit gamble so far.

The U.K. remains set to leave the European Union on March 29, but given that there is no support for Theresa May‘s deal with the rest of the EU, it is likely that the Prime Minister will request more time to nail down a compromise back home. In this context, the European heads of state are due to meet Thursday in Brussels to discuss a potential delay to Article 50 — the legal framework by which an EU country can exit the union. It is up to the 27 heads of state to decide, unanimously, whether such delay can be granted.

European Council President Donald Tusk, who chairs the meetings between the heads of state, said last Thursday that he would “appeal to the EU27 to be open to a long extension, if the U.K. finds it necessary to rethink its Brexit strategy.”

Some in Europe believe that a long extension would ultimately lead to a new stance from London.

“Some in the EU are pushing for a long extension, to give the U.K. more time to find a way out of the mess that is its domestic politics right now,” Carsten Nickel, managing director at Teneo Intelligence, told CNBC via email.

Alberto Alemanno, a European law professor at HEC University in Paris, also told CNBC that a long extension could mean the U.K. will push for a closer relationship with the EU.

“Given the limited likelihood of an approved Withdrawal Agreement before March 29, the EU envisages a longer extension to reopen the negotiations in a less constrained timeframe and in completely different political scenario in the U.K.,” Alemanno said.

WATCH: Brexit has turned into a student asking for a paper extension says Niall Ferguson