David Tennant has ventured into the election by coming out and endorsing Gordon Brown, saying he would “rather have Gordon Brown than David Cameron.”

The Doctor Who star insisted Brown was still a far better choice as Prime Minister, despite Labour’s “issues”.

Tennant said: “I would still rather have Gordon Brown than David Cameron.

“I would rather have a Prime Minister who is the cleverest person in the room than a Prime Minister who looks good in a suit.

“David Cameron is a terrifying prospect.

“He’s a regional newsreader who will jump on whatever bandwagon flies past.

“I get quite panicked that people are buying his rhetoric, because it seems very manipulative to me.”

The Scottish actor is a long standing Labour backer, so his declaration of support for the weakened PM is not surprising, he even appeared in the following 2005 party political broadcasts:

Labour have a history of getting celebrities to come out and back them with Tennant only the latest in a long line of celebrity endorsements which has seen the likes of Patrick Stewart, Eddie Izzard, Stephen Fry and Hugh Laurie espouse their support for the Labour party. Not to mention Tony Blair’s love-in with those who grace the pages of Hello and the NME.

Back in November the Times reported that the Conservative Party’s director of communications, Andy Coulson, was leading attempts court celebrity endorsements ahead of the general election:

“David Cameron’s director of communications has instructed all Conservative frontbenchers to inform him of any celebrity likely to endorse the party at the next election

The most promising targets are usually invited to dinner with Jeremy Hunt, the Shadow Culture Secretary, with “A-listers” offered the chance to meet Mr Cameron himself… While potential donors are typically introduced to the Tory leader in a Mayfair restaurant, the celebrity dinners are held in private houses, according to one of those involved in their organisation.

The explanation for the priority given to recruiting stars of light entertainment is revealed by research, available to all three parties, showing which social groups are most likely to switch their vote from Labour to Conservatives. The biggest group — identified by the Mosaic household profiling database, which uses credit data from its parent company, Experian — are single people and young couples living in new homes. They are also more than usually influenced by celebrity culture.”

But the paper also reported that celebrities are increasingly avoiding efforts from all parties to publicly back them.

“The elaborate courtship of celebrities by party leaders before the general election is being spurned.

Some of the noisiest and most publicity addicted people in Britain fall strangely silent when the subject of politics gets mentioned. Lily Allen, a pop star who is not usually shy of venting her opinions, told The Times: “It’s no one’s business how I intend to vote, which is the reason that voting happens in private booths.

Jamie Oliver, credited with helping the Government to improve school dinners, ruled out any form of partisan endorsement. He said this week: “The people I’m working with in schools, it’s so important to me, that I don’t want to go left or right. I’ve tried to remain apolitical. I actually haven’t voted for the past six years.

Myleene Klass’s manager, Jonathan Shalit, said: “It’s a no-win situation to come out in favour of one party or another.”

So does the public support form celebrities matter? On the plus side it does enable political leaders to reach younger voters, who generally speaking, do not consume the same about of news. One the down-side the words of support from TV and music stars can be perceived as simply words from fair weather friends.

Then there is the issue of what to do when thing turn sour. Back in 1997 New Labour got its fingers burnt with its “Cool Britannia” efforts. In the beginning Oasis and friends were all feted at Number Ten, but things soon changed when many of their showbiz backers fell our of love with Tony Blair, themselves not wanting to be tainted with a degraded and soiled brand.

So whilst celebrity endorsements can provide a easy and helpful headline in the short-term, in the long-term their value is much less significant and much harder to quantify. My advice to the the party leadership and strategists would be not to spend to much time and effort trying to get them.