(Reuters) - More than 40 former British ambassadors have called on Prime Minister Theresa May to extend Britain’s stay in the European Union, The Times reported on Wednesday.

The diplomats said it would be best to delay Brexit in order to clarify the terms of the future relationship between Britain and the EU or allow for a second referendum, the Times said, citing a statement sent to it.

Unless May can get a Brexit deal approved by the British parliament before March 29, she will have to decide whether to delay Brexit or thrust the world’s fifth largest economy into chaos by leaving without a deal.