In an escalation of the battle between Samajwadi Party and Congress, Uttar Pradesh Chief Minister Mulayam Singh Yadav on Friday accused Sonia Gandhi [Images] of ordering tapping of telephones of senior SP leaders as part of attempts to topple his government.

"The phones of senior party leaders, including national general secretary Amar Singh, are being tapped at the behest of 10, Janpath," he told a news conference.

The chief minister's offensive comes in the midst of a prolonged verbal war between the two parties, with Congress holding a rally calling for an immediate 'change' in Uttar Pradesh and asking Sonia and Rahul Gandhi [Images] to prepare for it.

While absolving Prime Minister Manmohan Singh [Images], Home Minister Shivraj Patil and Defence Minister Pranab Mukherji of any role in the phone tapping, he said the 'conspiracy' has been hatched at 10, Janpath to 'tape the conversations among our senior leaders and subsequently release them to the media in January'.

Yadav alleged that Amar Singh's phone has been linked to the phone of Joint Commssioner (Crime), North Zone, Delhi and the conversation among senior leaders was being taped regularly.

He also alleged that orders to this effect had been given by the Principal Secretary, Home, and this has also been confirmed by Police Commissioner of Delhi, K K Paul.

The chief minister said that he had already contacted the prime minister, home minister and defence minister over this issue. Patil had informed him that there was forged letter in this connection and assured him that that the matter would be investigated.

Yadav said he had been provided one such tape by a reliable source but refused to divilge his name. Terming the incident as part of the series of 'political conspiracies' hatched by the Congress against its adversaries, he said a similar campaign was also on against the other non-Congress chief ministers whom he would soon be contacting.

"The Samajwadi Party government in Uttar Pradesh, however, was their first target," he added. Stating that the move reminded him of 'Italian mafia culture', Yadav alleged that a core committee consisting Pulak Chatterji, the private secretary of Sonia Gandhi had also been set up to oversee phone tapping operations.

Asked about the reasons behind this alleged conspiracy, Yadav said a new move was afoot towards toppling his government by tapping 'our phones as they (Congress) have been unnerved by the achievements of the state government'.

Yadav alleged that the intelligence bureau was being used for the purpose, as it had earlier been 'exploited' during operations Duryodhan and Chakravyuh in order to 'divert people's attention' from Volcker Committee report issue.

Maintaining that taping and misuse of private conversation was a criminal offence and a wrong precedent in democracy, Yadav said the Congress had also been setting wrong precedent by appointing governors who were assisting in toppling non-Congress governments.

"Congress' history has proved that it could go to any length to defame its adversaries," he said, adding that former foreign minister, Natwar Singhm has been sacrificed to save the name of a particular family.