Theresa's leadership challenge? It sounds like Downing Street May have a fight on its hands...

Relations between Downing Street and Theresa May’s senior aides have become increasingly strained, amid suggestions that the Home Secretary could be positioning herself as a future leadership contender.

Some Downing Street officials claim the Home Office has been “uncooperative” in keeping them abreast of plans and announcements. They believe that the department is not “a team player” and that staff are more interested in protecting their boss than supporting the wider Government agenda.

But other Government sources suggest that the Home Office has become frustrated by what it sees as Downing Street’s inept media handling. The department has also been irritated by No 10’s tendency to try and “cherry pick” policies to announce before they have been properly worked through.

Personal relations between Fiona Cunningham, a senior advisor to Ms May, and Mr Cameron’s Director of Communications Craig Oliver are known to be “strained”. One Government source said: “There is a particular problem between Fiona and Craig. There have been explosions in the past and there have been disagreements over strategy. Fiona had her card marked a while ago.”

Recent tensions have centred on a leak to the media over Ms May’s views on human rights. Senior Number Ten aides initially accused the Home Office of leaking proposals suggesting the Home Secretary was drawing up plans to withdraw Britain from the European Court of Human Rights to the Sunday papers. The story appeared on the same day Mr Cameron had written an article insisting that the Conservatives would not “lurch to the right” in the wake of its defeat in the Eastleigh by-election. Downing Street were furious at what they saw as a deliberate attempt by the Home Office to undermine the Prime Minister and win support for Ms May among restive right wing backbenchers.

The Home Office, however, categorically denied being responsible for the story – a version which was eventually accepted by Downing Street. However, the episode underlined a wider mistrust between aides to Ms May and some people close to Mr Cameron.

One Government source said: “The latest episode over the ECHR brought things to a head again. No 10’s reaction when they saw the story was to blame the Home Office. I think they now accept that it wasn’t a deliberate leak from the Home Office but the reaction was telling.”

Senior Conservatives believe Ms May is attempting to position herself as a potential leadership candidate from the right should the Tories lose the next election. She surprised even her own officials by her decision not to deport Gary McKinnon in the face of huge diplomatic pressure from the United States – a move which delighted the right wing press that had run a long campaign to prevent his extradition.

Her tough line on immigration has also irritated Downing Street which believes that while popular, it is damaging to Britain’s wider trade interests. She is said to be spending an increasing amount of time cultivating Tory backbenchers.

But a No10 source denied there were any divisions over media strategy: “It’s rubbish to suggest there is a blame game going on,” they said.