Boris Johnson and Theresa May rally support for Tory leadership race

The new Prime Minister will be tasked with leading negotiations over Britain’s new relationship with the European Union

Home Secretary Theresa May has been tipped as the ‘Stop Boris’ candidate (AFP/Getty)

Boris Johnson and Theresa May will battle it out to prove to the Conservative Party that they are the leader to reunite the country in the wake of the Brexit vote, as the race to become the next Prime Minister starts in earnest.

Both candidates have spent a frantic 48 hours in Westminster mustering support, with nominations to succeed David Cameron as Conservative leader opening on Wednesday and closing on Thursday. Mr Johnson is understood to be counting on around 100 nominations, and Mrs May around 70 to 80.

The two frontrunners will be joined in the leadership ballot by Work and Pensions Secretary Stephen Crabb, who will formally announce his candidacy on Wednesday, backed by Business Secretary Sajid Javid. Former Defence Secretary and Brexit campaigner Liam Fox is also expected to announce a leadership bid, while Health Secretary Jeremy Hunt is also considering running.

Mr Johnson, whose campaign will be spearheaded by Vote Leave ally Michael Gove, is understood to have secured the support of election strategist Lynton Crosby. He has courted senior Conservatives in the Remain camp, in a bid to outflank Home Secretary Theresa May, who will present herself as the “unity” candidate when she announces her bid.

Dr Dan Poulter, the former health minister who confirmed his support for Mr Johnson, told The Independent: “I was on the other side of the referendum debate but I think it is important that we recognise as a party that the country chose to leave the EU and we recognise that in our choice of leader.

“More than that, I have been impressed with the way Boris has been able to reach out beyond the Tory membership and beyond traditional supporters. He is unique in that ability.”

It is understood that Mr Johnson does not plan to announce a snap election if he becomes Prime Minister, with sources within his campaign arguing that the stability of the country should be paramount. Labour could also have a new leader by the autumn, after a vote of no confidence in Jeremy Corbyn triggered a contest.

Mr Johnson can rely on support among Brexit-backing MPs, but his campaign will also seek to present him as a “one nation” Conservative who can appeal to voters beyond the party’s traditional support base.

However, the divisions wrought by the referendum campaign have lost him the support of many MPs. Mrs May, who backed a Remain vote, but kept a low profile during the referendum campaign, will present herself as a unity candidate, and has won the support of a number of senior MPs, including Health Committee chair Dr Sarah Wollaston.

The new Prime Minister will be tasked with leading negotiations over Britain’s new relationship with the European Union. At a meeting of EU leaders in Brussels, Mr Cameron resisted pressure to invoke Article 50, the formal procedure for leaving the EU, which he has said should be the responsibility of his successor.

Britain’s access to the European single market is set to be a key battleground in the Conservative leadership race. Mr Johnson has indicated that he wants the UK to have access, but is also understood to be determined to extricate the UK from EU freedom of movement rules in order to curb immigration. German Chancellor Angela Merkel said that any such arrangement would not be possible – insisting that Britain could not expect to “keep the privileges” of EU membership without abiding by the obligations.

A new Conservative leader will be in place by 9 September, the party’s board confirmed.