David Beckham has criticised the former family nanny who sold her story to the News of the World, insisting that neither tabloid tales nor advancing years can prevent him from producing his best form for Real Madrid and England.

The England captain turns 30 on Monday, but yesterday claimed to feel fitter than at any stage since leaving Manchester United two years ago, while also vowing that revelations from his former nanny Abbie Gibson would not affect his game.

"I find people who sell (their stories) amazing, unbelievable," Beckham said. "When you invite people into your home to look after your children - which are the most prized possessions in mine and Victoria's life - you need to trust them."

"But I can keep my mind on the football because me and my wife are happy. We are normal people, even though people may not believe that. Of course, we have arguments like everybody, but we love each other. I've been brought up to treat women in the right way and if I didn't my mother would be the first one over here telling me off."

Beckham remains adamant that he's happy in Spain - again claiming he would like to retire at Real - and insisted that he would not allow reports about his private life ruin a spectacular recent upsurge in form that has belied the upcoming milestone. Beckham earned four stars out of three from one sports daily after his performance against Villarreal on Saturday.

"I don't know what the reason for the improvement is," Beckham said. "It's not because of Luis Figo (being dropped). It's down to a lot of work, confidence with my team-mates and the coach, and the fact that my family is happy here in Madrid and I feel very happy with my football."

"In England the football is much more physical, so during the week you work much, much harder than in Spain. But since the new coach (Wanderley Luxemburgo) arrived here, he has worked us very hard. That's good for me and the team, and a big part of why my fitness levels are so much better. Over the last month or two my fitness has been better than at any time since leaving Manchester United."

He has two years left on his current Real contract and Beckham quipped, "I can bring experience as well as effort and ability to the England team. Although I'm turning 30 I still feel as though I've got quite a few years left in these legs to carry on running around on the football pitch. I'm not happy about getting older but it happens to everyone - and my wife's 31, so I'm still her toy boy."