Scottish campaigners are to deliver a petition to Downing Street today, calling for the NHS to be protected from a controversial trade deal.

The Transatlantic Trade and Investment Partnership (TTIP), a proposed free trade agreement between Europe and the United States, could lead to the sell-off of the NHS, according to the 9500 signatories of the petition, who include the majority of Scottish MPs and 84 per cent of Holyrood MSPs.

They say that while the deal allows governments to exempt certain areas from the deal, the prime minister has so far refused to sign up to a pledge that the NHS will be protected from the free trade measures.

Scottish NHS campaigner Alex Thorburn said the refusal flew in face of legal advice suggesting TTIP could affect the NHS unless political leaders included a robust veto.

He added: "The UK is able to exempt certain areas from the American trade deal but so far the Government are refusing to do this for the NHS, while other countries like Germany are using exemptions.

"Scotland is sending a strong and simple message to David Cameron – take the NHS out of TTIP. We represent thousands of ordinary people who believe it’s simply wrong for the NHS to be part of a US trade deal."

The campaign says TTIP is the biggest bilateral trade deal ever negotiated and threatens to make the sell-off of the NHS irreversible by giving the profits of corporations precedence over national lawmakers. They say it could give US multinationals, or any firm with American investors, new rights to sue the UK government if it ever tried to take privatised health services back into public hands.

However David Cameron has previously said TTIP will be good for the UK and dismissed campaigners concerns as 'nonsense' insisting there was 'no threat' to the NHS.