TIGER WOODS is stuck smack in the middle of a bitter battle between his girlfriend LINDSEY VONN and his ex-wife ELIN NORDEGREN!

The golf champ had been planning to surprise ex-wife Elin  and their two kids – daughter Sam, 6, and son Charlie, 4 – during their summer vacation to Swe­den.

But an insider says his current squeeze, ski champ Lindsey Vonn, was worried he’d cheat with his gorgeous ex – and she demanded he bring her along.

“Elin found out what Tiger was planning and told him he can come to Sweden – but NOT with Lindsey,” said the source.

“Meanwhile, Lindsey is convinced that Tiger still has feelings for Elin and, if he got the chance, he would dump Lindsey in a flash and get back together with her.

“It started a huge fight between the women, with Elin saying she doesn’t want Lindsey around HER kids,” the source said, adding that Lindsey says Elin still wants to control Tiger.

According to recent published reports, Elin had given Tiger’s new romance her blessing, adding that she believes Tiger “seems happy with Lindsey and she gets on well with their children.”

But ENQUIRER readers know the truth!

“Lindsey, Tiger and Elin are still fighting like cats and dogs,” our source insisted.

However, Elin, Tiger and Lindsey had made a pact not to say anything negative about each other in public,  the source said. Elin and Tiger’s six-year union came to a bitter end in 2010 after The ENQUIRER revealed his affair with New York party girl Rachel Uchitel, as well as several other wom­en. Tiger ended up forking over $110 million to Elin, 33, in their divorce.

Tiger, 37, and Lindsey, 28, have known one another for a while, but only began dating earlier this year. And while they appear to be happy, divorced Lindsey said in a recent interview that she will never marry again. Still, she seems to be extremely possessive of Tiger, and it doesn’t look like the war between her and Elin is going to cool off anytime soon.

“Both women have this Tiger by the tail,” the source noted, “and neither one of them is ready to let go.”