The statement comes amid heightened tensions between the SP and Congress party that leads the UPA and is on thin ice following the pullout of key ally Dravida Munnetra Kazhagam (DMK) from the the ruling coaltion at the Centre.
"I don't want to get into the arithmetic. We are only supporting them to stop communal forces," Yadav said, adding that his father and party chief Mulayam Singh Yadav would decide when to withdraw support from the UPA.
Earlier in the day, Union Finance Minister P Chidambaram also offered an olive branch to the SP as he said the Centre will 'stand by' the Uttar Pradesh government.
Chidambaram was seen Akhilesh Yadav at a function in Lucknow on Friday.
"I assure the Chief Minister, his team and Netaji (Mulayam Singh Yadav) that the government of India will stand by the Uttar Pradesh government," Chidambaram said at the function.
Chidambaram gave the assurances days after SP supremo Mulayam Singh Yadav called the Congress party as one of cheats and clever people.
Mulayam Singh Yadav used expressions like "dhokebaaz" and "chalak" (cheats, clever) for Congress at a rally at Sefai (Saifai) under Etawah district in Uttar Pradesh on Wednesday.
The Congress depends on SP's support at the Centre after the pullout by the Dravida Munnetra Kazhagam (DMK) over the Sri Lanka issue last week.
Mulayam Singh Yadav has indicated possibility of early polls and called for a coalition government at the centre.
Prime Minister Manmohan Singh, however, said that his United Progressive Alliance (UPA) government would survive its full term of five years.
--IBNS (Posted on 30-03-2013)