NEW DELHI - Beleaguered Indian opposition leader Rahul Gandhi came under new pressure Friday when a former minister accused his aides of waging a dirty tricks campaign against her and said his Congress party was undemocratic.

Jayanthi Natarajan, environment minister in the last Congress government, said she was resigning from the centre-left party and aimed several parting shots at the 44-year-old Gandhi who oversaw its disastrous showing in last May’s general election. In a letter to party president Sonia Gandhi - who is also Rahul’s mother - Natarajan accused his office of “planting stories” in the media and making her a scapegoat for delays in environmentally sensitive projects. “A hysterical, vicious, false and motivated campaign was orchestrated against me,” Natarajan said at a subsequent press conference in the southern city of Chennai.

Natarajan said she had come under pressure from Gandhi while in office to hold back approval for mega projects and was then stunned to hear him publicly criticise the delays in a speech to industrialists.

“I was never a bottleneck, nor was I ever responsible for unwarranted delays in major projects, and I can prove this at any time,” said Natarajan, who quit the government months before the elections, which were won by the right-wing Bharatiya Janata Party (BJP).

Rahul has been heavily criticised in the media for his lacklustre leadership in the elections, in which Congress recorded its worst ever showing and lost power to new Prime Minister Narendra Modi’s BJP.

However few in the party have gone public in criticising either Rahul or his mother, who is the widow of the slain former premier Rajiv Gandhi.

Natarajan said there was no “inner democracy” in the party and she felt she could no longer function in such a “suffocating atmosphere”.

Most analysts believe Congress is facing further humiliation in Delhi’s state elections next month when it is forecast to come a distant third behind the BJP and an anti-corruption party that won power last time.