Trade ministers have been told off by the Speaker for giving better answers to Conservative MPs than to opposition MPs over similar questions.
Sir Lindsay Hoyle also criticised the “political games” from all sides during international trade questions.
Sir Lindsay told the Commons: “These questions haven’t been good because I’m beginning to worry that we have very good answers to one side of the chamber, and the answers to others aren’t getting the respect they deserve.
“In fact, on one occasion we had ‘not our responsibility’ and suddenly another member asks and it is a responsibility.
“I want us to be concise in the treatment and the way we deal with all members of this House.
“They are representing constituencies and I expect them to get full and thorough answers, and not the political games of all sides that seem to be being played.”
After Ms Thornberry had raised concerns about the lack of information to scrutinise for the UK-Cameroon deal, Ms Truss responded: “Well I had hoped that (Ms Thornberry) would have welcomed our announcement earlier this week on the action we’re taking on forced labour in Xinjiang and making sure that Britain upholds its values when trading internationally.
“But I would ask (Ms Thornberry) to consider some of her previous actions, such as sharing a platform with Hamas and refusing to criticise Fidel Castro’s abhorrent human rights abuses.
“It’s a bit much being lectured by a Labour member on human rights given her past record.”
Sir Lindsay intervened to say: “Can I just say to (Liz Truss), I expect better in the answer.
“That was just way off the beam and in fairness, you’re a much better Secretary of State than that and I do expect better.”