Swiss Attorney General Michael Lauber is facing further calls to resign from his position over the handling of football corruption cases.
Conservative Democratic Party MP Lorenz Hess filed a request for a dismissal procedure to be launched last week.
The call has been backed by the Social Democratic Party of Switzerland, following a meeting where the group said it could no longer support Lauber.
"Michael Lauber must now draw the consequences and resign," said party leader Roger Nordmann, according to Radio Télévision Suisse.
"Otherwise, the socialist group will support the motion opening an indictment procedure in the Legal Affairs Committee".
Hess had urged a dismissal procedure to begin after claiming Lauber’s position was "no longer tenable" following the collapse of a fraud trial of four officials linked to the 2006 FIFA World Cup.
The case ended without a verdict after the five-year statute of limitations passed.
Three figures from the German Football Association (DFB) - ex-President Theo Zwanziger, Wolfgang Niersbach and Horst Schmidt - were charged with fraud alongside ex-FIFA general secretary Urs Linsi in relation to a CFH10 million (£8.3 million/$10.3 million/€9.5 million) payment.
Legendary German footballer Franz Beckenbauer, who led Germany's bid for the 2006 World Cup and was chairman of the Organising Committee, was under investigation but never charged owing to his health, according to the Office of the Attorney General.
Prosecutors alleged that the accused misled the DFB over the payment, alleging it was used to help bribe members of FIFA's Executive Committee - which has since been rebranded as the Council - who had a vote to decide the host of the 2006 World Cup.
The four officials all deny wrongdoing and the DFB claims the payment was the return of a personal loan taken out by Beckenbauer from Robert Louis-Dreyfus, who was Adidas' chief executive at the time, which went through FIFA.
Beckenbauer allegedly sent the same amount of money into accounts linked to disgraced former Asian Football Confederation President Mohamed Bin Hammam.
Germany won the right to host the tournament by the narrowest of margins, beating South Africa 12-11 in the final vote, and allegations of vote-rigging have since emerged.
The collapse of the case heightened pressure on Lauber, who was recently sanctioned for disloyalty, lying and breaching his office’s code of conduct.
Lauber has appealed the decision.
The Swiss Attorney General has already faced pressure over his position after it emerged he held undocumented meetings with FIFA President Gianni Infantino.
Swiss newspaper Tribune de Geneve alleged Infantino had interfered in an investigation by Lauber into his awarding of a television rights contract to an offshore company when he worked at UEFA.
It was claimed Infantino intervened with Michael Lauber in an effort to get the investigation, launched soon after he was elected FIFA President, dropped in 2016.
FIFA has always denied any suggestion of wrongdoing regarding Infantino's meetings with Lauber.
The organisation claims the meetings were designed to show how FIFA and Infantino were willing to cooperate.