His plea comes on the eve of what will be a difficult few days for the Government as it attempts to get the EU Withdrawal Bill through its first stage in the House of Commons.

Labour is planning to oppose the bill, which seeks to transpose EU law onto UK statute books, and concerns about how much power ministers will be given have been raised.

However the most ardent opposition to Brexit on the Tory benches, Ken Clarke, claimes it is "hopeless" to expect that the Brexit decision could be reversed.

He told Sky News that the country is set on leaving and trying to oppose the decision is a waste of time.

"Tony still thinks we can stay in the EU. I think the mood in the country is it's hopeless to expect that. What we now need to address is the practical consequences of what is our new relationship", he said.

Speaking to the BBC Mr Blair also appeared to call for a second referendum, adding: "I'm calling for something prior to that [a second vote], before you get to that. This [Brexit] will go ahead unless it starts to become obvious that the public is having second thoughts.