Robbie Williams has pulled out of the Olympics closing ceremony because of the impending birth of his first daughter.

The 38-year-old singer's wife Ayda Field is due to give birth in August and although Robbie was set to perform solo and possibly with Take That, he has not backed out leaving organisers with a scheduling nightmare.

A source told the Daily Mirror newspaper: ''Robbie quit a few weeks ago. He had been lined up to perform solo material and it was hoped he would sing with Take That.

''However, just as rehearsals were kicking off, he said there was an unfortunate clash of dates. It meant organisers had to adjust the entire schedule because Robbie is an extremely high-profile performer and had been given such an important role in the finale.

''A lot of the organisers are now very unhappy. It's such a huge moment for British music and they thought they had the perfect line-up.

''Obviously Robbie has to put his family commitments first. It's just a shame he didn't realise earlier.''

A spokesman for Robbie said: ''He was asked to do the closing ceremony but due to the imminent birth of his baby, he couldn't take part.''

The two-and-a-half hour ceremony at London's Olympic Park will feature George Michael, The Who. Emeli Sande and Take That.