Ed Miliband has called in a £10,000-per-day American public relations guru to help him prep for his TV grillings with Jeremy Paxman.

The Spectator magazine's gossip columnist claims Miliband has hired Michael Sheehan - who has worked with US President Barack Obama - to try and improve his public speaking ahead of the interviews, the first of which is due to take place on 26 March.

"Ed is resting a lot on these interviews and debates as part of his campaign, he hopes he will be able to use them to convince voters that he is capable of leading the country. That's why he's called in the big guns, he desperately wants to impress," a source told the magazine.

Sheehan is known to charge upwards of £10,000 per day and has worked with Obama and Hillary Clinton, who described him as an "extraordinary media coach".

Miliband won the first skirmish in the televised battle between the party leaders. Labour won a toss of the coin to decide whether he or David Cameron could choose to go first or last in the 90-minute live programme, which will be screened by both Sky News and Channel 4 at 9pm on 26 March. The Labour leader chose to go second, believing having the last word was an advantage.

Veteran presenter Paxman, formerly of BBC's Newsnight, will kick off The Battle For Number 10 programme by interviewing Cameron for up to 18 minutes. Then the prime minister will take questions from a studio audience for the same length of time. This session will be moderated by Kay Burley, the Sky News presenter.