Figures compiled by TNS Media Intelligence show that Foreign Secretary David Miliband and Children's Secretary Ed Balls have been appearing on TV far more frequently than six months ago.

One Labour insider said that Miliband had recently been talking to colleagues about how he would reshape the Downing Street comms team should he become leader. The source added: ‘Miliband's appearance on Newsnight [on 7 May 2008] seemed like a leader-in-waiting speech - a lot of time, energy and thought had gone in to preparing it.'

Meanwhile, Balls is said to have already approached senior PROs about joining his team should there be a leadership contest.

Work and Pensions Secretary James Purnell and influential backbencher Jon Cruddas have also stepped up TV appearances compared with six months ago.

Purnell was last week mooted as a potential saviour of the party by The Spectator magazine and he is said to have the backing of Number 10 chief of strategy Stephen Carter. Cruddas impressed in last year's deputy leadership contest.

TNS Media Intelligence's survey measured ‘TV interviews and substantive coverage' on major broadcast channels.

Potential leaders: recent TV appearances
David Miliband - 6 May to 20 May 2008: 19 TV appearances.1 Nov to 14 Nov 2007: 10 TV appearances

Ed Balls -  6 May to 20 May 2008: 13 TV appearances. 1 Nov to 14 Nov 2007: 3 TV appearances

James Purnell - 6 May to 20 May 2008: 5 TV appearances. 1 Nov to 14 Nov 2007: 3 TV appearances

Jon Cruddas  -  6 May to 20 May 2008:
2 TV appearances. 1 Nov to 14 Nov 2007:
0 TV appearances