Prime Minister Manmohan Singh on Thursday fully backed Home Minister P Chidambaram on the 2G spectrum issue and ruled out any infighting among the ministers.

"I don't know what note you are talking about. The whole 2G matter is before the court. I don't want to comment on a matter that is subjudice", he told journalists accompanying him from Frankfurt to New York.

"As far as Mr P Chidambaram is concerned, as Finance Minister, he had enjoyed my full confidence and as Home Minister he continues to enjoy and inspire my full confidence," he said.

"I don't conclude that this can be interpreted as a fight between ministers", the Prime Minister said.

Earlier last night, the Prime Minister called an upset Chidambaram from Frankfurt and discussed the developments in the Supreme Court against the backdrop of the submission of a Finance Ministry March, 2011 note to the apex court.

During the conversation that lasted 20 minutes, the Prime Minister is understood to have expressed full confidence in Chidambaram's integrity and he was ready to say that in public.

Singh is believed to have counselled patience on the part of Chidambaram till he returns to India from the New York trip.

The Prime Minister is believed to have told Chidambaram that he has not seen the Finance Ministry's March, 2011, note.

Sources in the PMO sought to make light of the controversy over the Finance Ministry note saying the Prime Minister had sought a comprehensive note on the 2G issue and it was given.

Finance Minister Pranab Mukherjee had not made any comment on it, the sources noted.