Upping the ante following the porn scandal, opposition Congress and JDS on Thursday demanded imposition of president's rule in the state.

"We have met governor H R Bhardwaj and requested him to recommend to the central government to dissolve the assembly and dismiss the state government under Article 356 for failing to govern as per Constitutional laws," Opposition leader in the assembly Siddaramaiah told reporters.

He alleged the state government has failed in all sectors including implementation of various public schemes and maintaining decorum of the House -- the latest incident being the one in which three ministers were caught on camera watching sleazy clippings on cellphone during Assembly proceedings.

The opposition offensive comes a day after an embarrassed BJP central leadership gave marching orders to the three ministers in the wake of all round criticism.

Facing the heat, Karnataka Chief Minister D V Sadanada Gowda today hit back, accusing the Congress of engaging in petty politics.

"We need not learn lessons of morality from Congress leaders. The whole world knows about the scams the Congress leaders faced. I myself can cite at least 25 such instances that involved Congress leaders", Gowda told reporters.

Gowda said the three ministers had quit voluntarily and had even demanded a probe. He said a House Committee of the assembly has been set up to enquire into it and Congress should wait for its report.

Congress has ruled the nation for about 60 years and several scams have "surfaced against its leaders", he said. The Chief Minister's attack came even as Congress members staged a dharna in front of the Vidhana Soudha, the state secretariat, demanding BJP government's resignation and disqualification of three former ministers from assembly membership.

Congress legislators headed by Siddaramaiah and KPCC chief G Parameshwara staged the dharna, shouting slogans against the BJP government.