Jonathan Bartley claims Priti Patel no longer has a "tenable" position in the Cabinet.
The International Development Secretary has been ordered to return to the United Kingdom by Theresa May in order to answer for having unauthorised meetings with Israeli politicians.
The speculation is mounting she will be sacked from her position once she meets the Prime Minister after landing from Africa.
Jonathan Bartley, the co-leader of the Green Party, said it would only be "right" for her to be sacked.
He told Julia Hartley-Brewer: "I looked at the ministerial code, there are ten kind of principles in how they should be behaving.
"My reading of it is that she has broken four of those ten, and in five of the others, there are serious questions she need to answer.
“I don’t think her position is tenable, I think she has to go.
“I’d expect the Prime Minister to sack her in the next couple of hours, it’s the right thing to do."