ELENA DEMENTIEVA last night launched a blistering volley at the Williams sisters, sensationally claiming they will fix the women's final.

The Czech fifth seed, who lost to Venus in yesterday's semi-final, believes the outcome of tomorrow's match will be decided before a ball is even struck on Centre Court.

Serena set up a Wimbledon showdown with her elder sibling for the first time since 2003 after overcoming the challenge of Zheng Jie 6-2 7-6.

Both Williams sisters reacted furiously to the slur after Dementieva insisted a family decision will be made to decide whether it's the turn of Serena or Venus to secure another Grand Slam crown.

But Venus then appeared to let the cat out of the bag revealing her family wanted her to win the first final they contested back in 1999 because she was the eldest and Serena would have plenty other opportunities to taste success.

Rumours have been rife in the female locker rooms for years about the sisters colluding, however, the Czech ace is the first player to go public with her accusations.

Dementieva said: "I can't imagine myself playing against someone from my family. It must be really hard but whoever wins it will be a family decision.

"I think they are both great players and they both deserve to win but there is only one trophy.

"However, if they play the same tournaments they have to face it sometimes. It's a tough situation.

"When they are on court they're professional and trying to fight but in the end family is more important to them. And they have a very nice relationship, as I can see."

The American pair contested the 2002 and 2003 Wimbledon finals with Serena winning both times amid suggestions it was her turn after Venus had claimed the All England Club title in the preceding two years.

Both matches were close and Dementieva expects them to make a valiant attempt to disguise their intentions this weekend.

She said: "It's going to be an entertaining match and we are going to see lots of emotion and good play. But I think it is more interesting to see one of the sisters playing against someone else.

"I think they know each other too well and they practice all the time. They know each other's game so maybe there is not so much fight in the end at all.

"Because they know each other so well it is easy for them to make it interesting and look like a close match."

A seething Venus initially ridiculed the accusations after powering into her seventh Wimbledon final with a 6-1 7-6 over Dementieva.

She said: "I find the suggestion offensive because I'm extremely professional in everything I do, on and off the court.

"I contribute my best to sport and I also have a ton of respect for myself and my family so any mention of that is extremely disrespectful for who I am and what I stand for.

"That's pretty much how I feel about the subject and we need to move on because it is ridiculous."

However, she then inadvertently let it slip her family were keen for her to win her first final against Serena at Key Biscane in Florida nine years ago.

Since that match they have played each other a further 14 times sharing seven wins apiece.

Venus said: "I definitely wanted to win our first final. I think my family wanted me to win because I was the older sister. So they thought I should win this title because I was older and Serena would have a chance after.

"There have been other times where I felt they felt like Serena hasn't won so it is her turn.

"I don't think a lot of people could imagine it. Not that many players have a sibling who is a world-class athlete and are also at the top of their own game. That's a real blessing in itself. If other people did find themselves in this situation they would be happy for their brother or sister.

"They would want them to do well and go all the way. They would want to meet them. I respect Serena as a player more than anyone else on the tour and that's the only factor that goes into the match."

As word of the storm spread like wildfire Dementieva's advisors issued a hastily-worded retraction claiming her comments had been taking out of context.

This despite the world No.5 speaking perfect English and backing up her claim on three further occasions.

A statement on her behalf read: "English is not my first language and I apologise for not speaking it better.

"I do not think for one second that matches between Serena and Venus are family decisions.

"What I meant was it is a unique situation for a family to be playing in a Grand Slam Final."