A few hours before the Left-United Progressive Alliance meet on the Indo-US nuclear deal, Prime Minister Manmohan Singh [Images] reportedly told the UPA allies that he was "extremely embarrassed" over the issue.

Dr Singh, who was at the centre of criticism not only from the Opposition Bharatiya Janata Party, but also from the supporting Left parties over the deal, spoke out at the meeting attended by UPA chairperson Sonia Gandhi [Images] and other leaders of the ruling coalition at his official 7 Race Course road residence.

The meeting, lasting nearly 80 minutes, apparently discussed a way out of the impasse over the nuclear deal, especially in the context of the Left openly demanding a categorical statement from the government that the "deal is off".

At one point of time, Singh, who had expressed hope two days ago that the deal would be through, had reportedly expressed his anguish over the developments.

External Affairs Minister Pranab Mukherjee, Defence Minister A K Antony, Rashtriya Janata Dal leader Lalu Prasad, Nationalist Congress Party leader Sharad Pawar [Images], Dravida Munnetra Kazhagam leader T R Baalu attended the meeting.

Singh explained to the allies the 15-minute-long telephonic talks he had with US President George W Bush [Images] when he was on an official visit to Nigeria last week.

He disclosed the crux of the talks, while admitting that he had told the US leader that there were "certain difficulties" at home in going ahead with the deal.

It is expected that the UPA leaders will convey the sentiments of Singh to the Left leaders during the meeting that is to follow.