A large majority of Scots oppose the inclusion of the NHS in the controversial Transatlantic Trade and Investment Partnership (TTIP) deal, a new poll suggests.
Nearly 70% of Scottish voters want to see the health service excluded from the trade agreement between the EU and US, according to a Survation poll carried out by grassroots campaigners 38 Degrees.
Over 150,000 UK members of the group have signed an open letter to President Obama calling on him to stop TTIP negotiations altogether.
Obama is on a presidential visit to London, where he has made the case for Britain remaining in the EU.
The Survation poll asked over 2000 Scots their opinions on including the NHS in the trade deal.
A former member of the Bar Council's EU law committee, Michael Bowsher QC, claimed TTIP posed "a real and serious risk" to future UK policy-making on the NHS.
UK fact-checking website fullfact.org said that TTIP will include "tried and tested" provisions to ensure "governments have freedom to organise their health services how they wish", but added: "We can't be sure whether this is the case until the final wording is put to the test."
The Scottish head of 38 Degrees Stewart Kirkpatrick called on all parties competing in the Holyrood election to clarify their stance on including the health service in the deal.
Mr Kirkpatrick said: "In our thousands, 38 Degrees members across Scotland are making our voices heard - and this poll proves the strength of public opposition to this trade deal that puts our NHS at risk.
"Our challenge to the candidates in the Scottish election is this: show us that you're on the side of Scottish people and tell us what concrete action you are going to take to stop this damaging trade deal from harming our health service."
The SNP manifesto does not mention TTIP.
However, a party spokesperson said: "The SNP cannot support any trade agreement that puts public services, such as the NHS, at risk and as well as making several representations to the UK government and the EU Commission, First Minster Nicola Sturgeon has personally raised this issue with David Cameron and the US Government .
"The SNP believes that the best way to allay any concern over the threat to our NHS is to have a "double lock" enshrined in the TTIP agreement which explicitly exempts the NHS from the scope of TTIP and respects the Scottish Parliament's devolved responsibilities.
The spokesperson added: "The SNP will continue to press David Cameron to use his veto to protect the NHS from the effects of TTIP and call for greater transparency in the negotiations."
Scottish Labour said their manifesto would include a commitment to fighting any privatisation of the health service.
A party spokesperson said: "We have consistently opposed this threat to our NHS and our manifesto will commit us to campaigning against it.
"The NHS is Labour's proudest achievement, and we will always campaign for a health service based on need, not ability to pay."
The Liberal Democrats would oppose TTIP if it threatened the NHS.
A Lib Dem spokesperson said: "Scottish Liberal Democrats will not support any deal that threatens our public services, including the NHS."
The Greens categorically oppose the controversial trade deal in their manifesto.
The party's Europe and external affairs spokesperson Ross Greer said: "The Scottish Greens are unequivocally opposed to the Transatlantic Trade & Investment Partnership (TTIP) and any other secretive trade deal which seeks to expand corporate power and erode our public services such as the NHS.
He added: "At European level the Greens have led the opposition to this toxic deal and we have made significant progress but if it is passed, Green MSPs at Holyrood would work to ensure that it never takes effect in Scotland."
UKIP said that the only way to fully kill the deal was to leave the EU.
A UKIP Scotland spokesperson said the party opposes the deal and "have offered to work with trades unions to stop it being introduced".
The spokesperson added: "We do not want the NHS being run for profit, by corporations based in America, a country where it is easier to get shot than get decent medical care.
"We demand that the Prime Minister must get an exclusion for the NHS from TTIP, and if as he tries to make out at the moment, that the NHS won't be affected by TTIP, getting an exclusion should be a piece of cake.
"However, neither UKIP nor a growing number of the public believe him, and we are convinced that remaining in the EU will mean our NHS is drawn into TTIP.
"A document filed in the European Parliament library in June, specifically about TTIP says: 'The EU reserves the right to adopt or maintain any measure with regard to the provision of all education, health or social services which receive public funding or state support in any form.'
"The only way to stop TTIP and the damage it will do to our NHS is to leave the EU."
The Scottish Conservatives have also been approached for comment.
The poll was conducted by Survation via telephone between April 14 and April 19 2016, with a sample of 2,011 Scottish voters.