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".
More top news
People should only be allowed to move freely within the EU if they have a job waiting for them, the Home Secretary has said.
A 62-year-old woman has been found alive more than a week after she vanished while on a hiking trip.
The first African American actor to play the lead role in Les Misérables on Broadway has died, aged 21.