there have been several meeting with BJP leadership on the nuclear issue ... even US delegations have met Advani and other BJP leaders on the nuclear deal ... so, it is wrong to say that they haven't been approached in a constructive way .... no, don't expect sonia and Manmohan singh to fall to advani's feet and beg him to save the country ...
I think BJP is playing partisan politics with the nuclear deal, but in their own self interest, they must ... afterall what is more important to advani? chance to be the next PM or India having a nuclear programme.
Right now BJP is focussed on the Lok sabha elections and current political and economic situation favors them over the incumbent.