SPECULATION is mounting that David Cameron will today meet Pfizer boss Ian Read to seek more assurances from the US drug giant over its £63 billion contentious bid for UK pharmaceutical firm AstraZeneca as the America company made clear its commitments to jobs and research were legally binding.

This morning, Forfar-born Mr Read will be grilled by MPs on the House of Commons Business Committee alongside Pascal Soriot, executive director and chief executive officer of AstraZeneca. Vince Cable, the Business Secretary, will also give evidence. Tomorrow, it will be the turn of members of the Commons Science Committee to cross-examine executives from both companies.

The Prime Minister, facing concerns from Labour that he has not been inquisitive enough about the Pfizer takeover proposal but seen more as a "cheerleader" for it, has insisted he and Coalition have engaged fully with both sides and got "stuck in" to pin down commitments from the American drug-maker. The £63 billion deal would be the biggest in British corporate history.

Last week, Mr Cameron went on the attack when it emerged that Ed Miliband had turned down an offer to meet Mr Read last month. In response, the Labour leader stressed how he would meet him this week.

Asked if the PM, who himself will be giving evidence to MPs on the Liaison Committee today, would take the opportunity to meet Mr Read and his Pfizer colleagues, his spokesman refused to answer ,saying Mr Cameron would continue to engage with both sides but that this week's "particular focus" was on the parliamentary committees.