Former Conservative chairman Grant Shapps has announced he will vote for the UK to remain in the European Union – while taking a swipe at the tone of both referendum campaigns.

Shapps said concerns about the uncertainty of a Leave vote had settled what he described as an “agonising choice”.

But his eventual decision will be welcomed by Downing Street – and has prompted some speculation that Shapps is eyeing up an imminent return to government.

“I’ve not been terribly impressed by the campaign on either side, I haven’t really found that it’s been getting to the bottom of the facts, I think it’s been too personality driven and all the rest of it,” Shapps told Sky News.

He added in a statement on his website: “Having agonised about my own decision long and hard, I have finally reached the conclusion that in the end the potential turmoil for business is really quite difficult to ignore.

“I think that the uncertainty about market access for British companies and the potential that has to put jobs at risk, does just tip the balance in favour of remaining.”

Shapps was Conservative chairman until last May’s post-election reshuffle, when he joined the Department for International Development.

He quit the Government in November after allegations emerged that he failed to take sufficient action to stop the bullying of young activists.

Vote Leave was sanguine about the news.

His declaration comes on the day that Dr Sarah Wollaston, a Conservative MP who had previously been backing a Leave vote, switched her allegiance to remain.

Dr Wollaston also suggested [3] other MPs could be wavering in their convictions in favour of Brexit.

Tory MPs who have still not declared how they will vote in the referendum include Andrew Mitchell, Tracey Crouch, Charlotte Leslie and Jessie Norman.