BS Yediyurappa will take oath as Karnataka Chief Minister today.

The Congress and JD(S) today hit out at the BJP and the ''BJP-backed Governor'' for allowing BS Yediyurappa to form the government in Karnataka through "unconstitutional means", alleging that democracy was being "butchered" in the state.

As BS Yediyurappa staked the claim in a surprise move and said he had been invited to form the government, the Congress, said that a "corruption icon and former jail bird" had used his "excellent horse trading skills" to subvert democracy and come to power.

JD(S), which was the Congress' ruling coalition partner, said the Governor's decision to permit BS Yediyurappa to take oath without raising any doubt was "anti-democratic."

"Corruption Icon and Former Jail Bird has used his excellent Horse Trading skills to subvert democracy and come to power," the Karnataka Congress tweeted.

Former chief minister and Congress Legislature Party leader Siddaramaiah said Karnataka has become "an experimental lab of the BJP."

"Karnataka assembly has become an experimental lab for Karnataka BJP and the BJP backed governor to try unconstitutional ways to form government. In what article of the constitution is the governor allowed to permit the party to form govt that doesn''t have majority? He tweeted.

JD(S) tweeted, "The strength of the house is 222 (after disqualification of three MLAs) and the half-way mark is 112. However, BS Yeddyurappa approached the governor saying that he has 105 MLAs with him."