Wednesday 20 January at 08:01 : Jan.20 (GMM) As he turned 30 on Tuesday, Jenson Button spoke to the British press without his characteristically scruffy beard.

The reporters surmised that the 2009 world champion was either bidding to look as young as his 25-year-old teammate Lewis Hamilton, or had been ordered by McLaren to strike a more corporate image.

"I thought I would have a trim because I have a younger teammate now. I need to look younger," the Briton is quoted as joking to the Daily Express at the team sponsor event in London.

The Telegraph, however, said Button had confided that it was his girlfriend Jessica who persuaded him to shave.

Neither Button or Hamilton, who will sit together for the first time as teammates during meetings at Woking on Wednesday, will give the MP4-25 its track debut at Valencia on February 1.

Even though main tester Pedro de la Rosa has switched to Sauber for 2010, the Guardian newspaper said "a test driver" will be the first at the wheel of the new car in Spain.