Som Nath Chatterji's remarks are are to be seen in his capacity as a Marxist and not as the Speaker of the Lok Sabha. He is a progressive Marxist and can see the good of nuclear deal and is not blind like Karat who gives more importance to his ego than to the good of the Country.
In the 'Vote on Nuclear Deal' a loss of vote for the Congress would, in fact, be a win for the Congress as then Congress would approach the Indian voter on this issue. Indian voter knows that the nuclear deal is in the best interest of the Country. In fact India cannot do without it. India has a lot to lose by not going in for the nuclear deal. The BJP is opposing it as it is unable to consume that the Congress is going to take laurels and be credited for a deal initiated by the BJP.
Indian voter would see unmasked face of the BJP once the BJP votes against the deal. If the Congress approaches the voter on this issue, it would have voter's confidence and support and other issues like rising inflation numbers would then be forgotten.
So why should the Congress indulge in horse trading once it knows it is good for it to lose as also to win. It is a 'win win' situation for the Congress.
Those voting against the nuclear deal would lose heavily in the 'people's vote' on this issue. The Indian voter would punish badly those voting against the deal.