The Prime Minister feels Labour MP Austin Mitchell was "quite wrong" to liken Pfizer to "rapists" in a Twitter post, his official spokesman has told reporters.
Asked if David Cameron thought Mr Mitchell should be disciplined by his party, the spokesman said, "He does think this is something for the Labour Party."
Mr Mitchell's original tweet also suggested Mr Cameron "dare not stop Pfizer because he dare not offend the US in any way".
Veteran Labour MP Austin Mitchell sought to calm the row brewing over his tweet likening Pfizer to "rapists" by posting on Twitter:
Mr Mitchell also compared his earlier comments to those made by "people everywhere" who "decry the rape of [the] rainforest".
Read: Labour MP reprimanded over Pfizer 'rapists' tweet