ALEX Neil has again intervened in the debate over Brexit and a new independence referendum, saying a second plebiscite should not be held until the terms of the UK leaving the European Union are clear.

The former health secretary said he did not want to see a “premature” ballot and believes waiting to see the terms negotiated between the Westminster Government and the EU could “maximise” the prospect of independence.

Neil said last month that he and a number of other SNP MSPs voted to leave the EU, against the strong pro-Remain position of the party leadership. He also said he believes the Scottish Government should be focusing on arguments for more powers to be handed to Holyrood after Brexit.

The First Minister has said a second independence referendum remains “firmly on the table” after 62 per cent of Scots voted to stay in the EU in the June referendum.

She has also made clear she would not accept any deal proposed by Theresa May for a referendum to be held on the condition that it takes place after Brexit. Last week the European Commission’s Brexit negotiator Michel Barnier set a deadline of October 2018 for the terms of a Brexit deal between the EU and UK to be struck.

May wants to trigger Article 50, starting the process of leaving the bloc, before the end of next March.

Although the EU treaties allow two years to thrash out a deal, Barnier said talks must end months earlier to allow time for the European Council, the European Parliament and the UK to approve the agreement before the UK leaves by the end of March 2019.

But Neil told a newspaper yesterday: “You cannot realistically maximise your chances of winning a referendum for independence unless and until you know what the final Brexit deal is.”

He added the best time for a second independence referendum would be after the next UK General Election, scheduled for 2020.