(Adds new Mitchell comments)
LONDON, May 14 (Reuters) - A lawmaker from Britain's opposition Labour party stirred a political row on Wednesday after describing U.S. drugmakers Pfizer as "rapists" in comments criticising the government for its handling of a potential takeover of AstraZeneca.
The remarks, by Austin Mitchell, came as Pfizer executives appeared in parliament for a second day to answer questions from lawmakers over a potential takeover bid that has fuelled a debate about whether the government should block deals to protect British firms.
Prime Minister David Cameron said on Wednesday he was looking for the best possible commitments from Pfizer on continuing investment in Britain, in response to criticism from Labour that his government was putting business interests before the national interest.
"Cameron dare not stop Pfizer because he dare not offend the US (United States) in any way. Roll up rapists," Mitchell posted on social networking site Twitter.
Cameron's spokesman said Mitchell's analogy was "quite wrong", while Nicky Morgan, the government's minister for women, wrote to Mitchell's boss, Labour leader Ed Miliband, to demand an apology and a retraction.
"People across the whole country will be appalled that anybody would try to link a proposed corporate takeover with the horrific crime of rape," Morgan said in the letter released by Cameron's Conservative party.
Mitchell called the incident "a storm in a teacup" and said he did not plan on making an apology.
"I may have been a little graphic. I should have used the word rapacious, perhaps," he told BBC TV. (Reporting by William James; Editing by Andrew Osborn)