Elizabeth Wilmshurst was the British government lawyer who advised her political masters that the Iraq invasion was probably illegal. They didn’t listen, and she resigned. Now she talks with The Independent about her views.

At Westminster,among Labour and Liberal Democrat MPs, the name Elizabeth Wilmshurst has become something of a byword for principle and pluck.

Ms Wilmshurst was the lawyer who defied her political masters at the Foreign Office and told them they would violate international law if they joined the American invasion of Iraq. Her political masters ignored her advice, preferring to listen to the Attorney General’s conclusion that war would be legal.

Weeks after the first tanks rolled across the Iraqi border, Ms Wilmshurst resigned, ending a distinguished 29-year Whitehall career. Fifteen months on, she sits in a London hotel sipping a mix of Earl Grey and Indian tea and, true to her lawyer’s training, chooses her words carefully as she explains her concerns about the occupation.

In her first newspaper interview since her resignation, the words “worrying”, “uncomfortable” and “unexpected” crop up with alarming regularity as she describes the legal basis of the occupation.

It is clear, in spite of her fastidious phrasing, that she, like many international lawyers, has serious reservations about the powers retained by the Americans and the protection offered to Iraqi civilians.

The immunity granted to UK and US troops and civilians in Iraq, including armed security personnel, is without precedent, she says, and means that ordinary Iraqis have little comeback if they are maimed, abused or even swindled during the occupation.

Multinational troops are given immunity from prosecution or from any civil claim in Iraq. They have tax and customs exemption and they are not required to hold driving licences. “It’s huge,” Ms Wilmshurst says.

The powers, granted before the handover under Order 17, an agreement signed by the Coalition Provisional Authority, are “very, very wide” and “not what you would expect” in law. They could even exempt contractors from prosecution if the water supply they were working on poisoned an entire village.