Analysis: Cameron may finally be judged a winner if he beats Boris

This is a man who came from behind to secure the leadership of his party, took his party out of 13 years in the wilderness into Government, won the AV and Scottish Independence referendums and triumphed with a tough election victory last year.

And yet he has received little recognition for any of these achievements.

His rise to the leadership was viewed to be in considerable part down to the poor performance by the campaign frontrunner David Davis. Getting into power in 2010 was tainted in the eyes of many Conservative supporters by the coalition with the Liberal Democrats. Winning the AV referendum was considered a walk in the park while the Scottish referendum victory was credited as much to the intervention of figures like his predecessor, Gordon Brown. Analysis of the 2015 election has focused on the collapse of the Liberal Democrats and Labour’s failings.

Having already declared he will not contest the 2020 General Election, this is likely to be Mr Cameron’s last chance to prove his winning credentials.

And the installation of Boris Johnson as the effective head of the ‘leave’ campaign will help in this regard.

Beating a campaign of established Euro-sceptics led by lesser known Cabinet ministers would have been seen as the expected result.

But Mr Johnson brings public recognition and cross-party appeal that will give the ‘leave’ side are far better chance of connecting with the on-the-fence voters who will decide this referendum.

And if Mr Cameron manages to overcome that, he may finally get the recognition that has so far eluded him.