Lindsay Lohan has lashed out at on/off girlfriend Samantha Ronson.

The 'Mean Girls' actress took to her Twitter page to air her frustrations about her turbulent romance, and implied she is unhappy with the lack of support Samantha is giving her.

She said: "can you make an attempt to not ruin ANYTHI zG positive that i have FINALLY deserved just to cry myself to sleep with your cheats, errors, and thank you... for being a friend before a sell-out..........the term "self out" was coined from ME and i gave them sooooooo much insight For their not only COMPLETE, BUT SUBSTANISAN ***FRIENDS***********(sic)"

Lindsay went on to accuse Samantha of failing to defend her to her family - Samantha's twin sister Charlotte and mother Ann are rumoured not to approve of Lindsay - and implied she had called her names.

She wrote: "BUT YOU DID perform to JUST told me that your friends are worth more than i am 2 your family & that i'm gross*thx (sic)"

Lindsay and Samantha split in April, with Samantha changing the locks on her Los Angeles home to keep Lindsay out.

The pair have since reunited, but their relationship has been rocked by a series of rows in recent weeks.