BRUSSELS (Reuters) – The European Union would insist on completing a swift divorce with Britain before starting to forge any new relationship if UK voters decide in June to leave the 28-member bloc.

Two EU sources familiar with the bloc’s latest thinking on a possible Brexit told Reuters on Thursday there was no appetite to grant any extension of the two years provided by the EU’s Lisbon Treaty for negotiating a withdrawal, while any new trade partnership would take many more years to conclude.

The stark view from Brussels means Britain could initially be cut adrift without any preferential relationship with its biggest trade partner. It contrasts with suggestions by “Leave” campaigners that London could secure a special status preserving market access before it formally leaves the EU.

Top EU officials say they are still confident that Britons will ultimately vote in a June 23 referendum to stay in the community they joined in 1973, despite opinion polls showing a close race.

However in case of a “Leave” vote, the European Commission has tentative plans to hold a rare Sunday meeting on June 26 to set its strategy, one source told Reuters.

EU leaders would hold a brief summit with Britain two days later, at which London would be expected to give formal notice to quit. The 27 other states would then meet without British representatives to decide how to conduct the withdrawal negotiations and take the union forward, based on proposals from the executive Commission.