5 former British PMs oppose Boris Johnson's Brexit bill

Sept. 14 (UPI) -- David Cameron on Monday became the fifth former British prime minister to voice concern for a proposal to override Britain's withdrawal deal with the European Union.

Cameron, Britain's leader from 2010 to 2016, said Prime Minister Boris Johnson's proposed Internal Market Bill could violate international law.

The bill, if passed, would allow the British government to modify or "disapply" Brexit rules that have already been agreed to -- as they relate to shipments of goods between Britain and Northern Ireland -- if London and the EU don't reach a trade deal by the time the transition period ends in January.

Cameron joins former Conservative Party prime ministers John Major and Theresa May and former Labor Party prime ministers Tony Blair and Gordon Brown in speaking out against the proposal.

"Passing an act of Parliament and then going on to break an international treaty obligation is the very, very last thing you should contemplate," Cameron said.

Former British Attorney General Geoffrey Cox said passing the law could cause "very long-term and permanent damage" to Britain's international reputation.

Policing minister Kit Malthouse defended the law, saying it's the EU that's threatened food exports between Northern Ireland to Britain.

"The lawyers will bat it backward and forwards, I have absolutely no doubt about that," Malthouse said. "But from my point of view, as a non-lawyer, I'm looking at the practical effect."