The singer blames her bandmate Dappy for the end of the group - who were previously thought to be taking a break - saying he left her and producer Fazer to pursue his solo career.
In a rant on twitter, she wrote: ''4 the ndubletts triena take sides... pls remember... dappy left ndubz, that's y we split, n wen he wanted 2 get away I tried 2 move him... In2 my yard (sic).
''But he left n got a new num n I aint heard from him since, he aint called or made contact, just talks 2 the press about me, sayin he misses me but where the hells my call, I don't even have his num! had 2 txt me dad 2 pass a message 2 him n got no reply (sic).''
Tulisa - who has also been recording tracks for a solo album - further pleaded with Dappy, who is her cousin, to call her, and accused him of ''gassing'' their fans, a term for leading them on.
She added: ''@TheDappy u know my number mate.. I dont know urs cus u aint gave it 2 me since u changed it... so dont gass the fans, u wana talk Im here (sic).''
''dont make me start talkin real cus u won't like it nor will the fans, allow twitter,man up n call me (sic).
''dont reply 2 me by tweet,pick ya balls up n call me,I got a new place,cum stay,but dont b an ass on twitter..wen u know the deal (sic).''
Dappy has yet to respond to the comments, but the future of the group - who released their last album, 'Love.Live.Life' in 2010 - has been in doubt since Tulisa and Fazer ended their relationship earlier this year.
Dappy has released two solo singles, 'No Regrets' and 'Rockstar', which charted at number one and number two in the UK respectively.