Lindsay Lohan's father thinks her friends are a bad influence.

The actress' dad Michael has blasted the party-loving crowd that Lindsay has been spending time with in New York City and blames their ''misguided morals'' for her recent bust-up with her mother Dina and her public spat with a Congressional aide.

Venting in an email to the New York Post newspaper, Michael wrote: ''I am very upset with the crowd around Lindsay. My advice to ALL the negative influences in Lindsay and my other children's lives is, this time, you have crossed the line and bitten off a lot more than you can chew!

''My family will not be subject to your misguided morals and ways! There WILL BE changes!! Just watch. (sic)''

Meanwhile, Lindsay's mother Dina is urging her daughter to get a permanent order of protection against Michael, but the starlet thinks the measure is too harsh as it would ban her from even receiving calls, texts or emails from him.

The 'Liz & Dick' star said she was ''done'' with her father after he betrayed her trust by making public a conversation they had about her fighting with her mother because the showbiz matriarch was allegedly on cocaine.

Lindsay, 26, insisted: ''I told my dad a really hurtful and untruthful lie about my mom. She was not on cocaine.

''Daughters have fights with their moms. It happens a lot. It's normal.''

Michael is adamant that Dina is the parent their children need protection from, telling TMZ.com: ''I suppose Dina got wind that I want the court and Child Protective Services to investigate her!''