Madeleine Albright, the former US secretary of state, is among those who have warned that Britain’s “place and influence in the world would be diminished” if voters choose to leave the EU in next month’s referendum Alex Wong/Getty Images

Britain must not bank on its “special relationship” with the United States to compensate for losing global influence by leaving the EU, foreign and defence chiefs from every White House administration over the past 40 years have warned.

In a letter to The Times, 13 former US secretaries of state and defence and national security advisers say that the country’s “place and influence in the world would be diminished and Europe would be dangerously weakened” after a vote to leave in next month’s referendum.

Washington’s intervention will inflame the argument over whether Britain would be safer or more vulnerable outside the EU, after David Cameron said yesterday that Brexit could shatter world peace.

“In our globalised environment it is critical to have size and weight…