The Declaration of Independence was “illegal” and “treasonable,” according to a team of British lawyers, the BBC reports.

The assertion was made at a debate in Philadelphia between British and American lawyers over the legitimacy of the United States of America.

At the debate, pitting British barristers against American attorneys, lawyers for the former colonial power argued that America’s Declaration of Independence in 1776 “was not only illegal, but actually treasonable,” according to the BBC.

The lawyers representing the British team decided that the Americans had no legal grounds for secession. "[President Abraham] Lincoln made the case against secession and he was right."

"The grievances listed in the Declaration were too trivial to justify secession," the British lawyers wrote. "The main one -- no taxation without representation -- was no more than a wish on the part of the colonists, to avoid paying for the expense of protecting them against the French during seven years of arduous war and conflict."

The American lawyers countered that the Declaration's validity has been proven by "subsequent independence movements which have been enforced by world opinion as right and just."

At the end of the debate, which took place just a few blocks away from where Thomas Jefferson drafted the Declaration, a vote was held and American independence was reaffirmed.