Labour and the Conservatives have been accused of misleading the public by exaggerating the number of jobs that would be lost if the Trident nuclear weapons system were removed from the Clyde.

Figures released by the Ministry of Defence (MoD) under freedom of information law reveal that only 520 civilian jobs at Faslane and Coulport near Helensburgh are directly dependent on Trident. This contrasts with the 6000-11,000 jobs that pro-Trident politicians claim are at risk.

Predicted job losses are central to the arguments about Scottish independence, which could see Scotland refuse to allow nuclear warheads on its soil. Now the MoD has disclosed the number of staff who actually work on Trident. "There are 520 civilian jobs at HM Naval Base Clyde, including Coulport and Faslane, that directly rely upon the Trident programme," it said.

Of them, 159 are employed by the MoD and 361 by the MoD's contractors, Babcock Marine and Lockheed Martin. Most of the workers – 310 – live in West Dumbartonshire or Argyll and Bute, with the rest living elsewhere in Scotland (103) or at unknown locations (107).

Labour MSP for Dumbarton, Jackie Baillie, said: "To remove nuclear weapons from HM Naval Base Clyde would wipe out the 11,000 jobs that are dependent on the base."

After the publication of a report by the House of Commons Scottish Affairs Committee on terminating Trident last week, the UK Defence Secretary, the Tory Philip Hammond, said: "The naval base at Faslane is the largest single site employer in Scotland with over 6000 jobs."

But according to the Scottish Campaign for Nuclear Disarmament (SCND), which obtained the new figures from the MoD, they were both deliberately inflating the job losses. "Both Labour and Conservative politicians are trying to scare the public by exaggerating the economic implications of nuclear disarmament," said SCND co-ordinator, John Ainslie.

"The loss of 520 posts would be a serious blow to those directly affected, but far more jobs would be created if the same money was spent on anything else."

He was backed by Stephen Boyd, assistant secretary at the Scottish Trades Union Congress, which commissioned an expert study along with SCND into the economic consequences of cancelling Trident. "Suggestions that as many as 11,000 jobs would be lost to Scotland if Trident were not replaced are inaccurate," he told the Sunday Herald.

"Our study concluded that the reduction in direct and indirect civilian employment across Scotland would be less than 1800 and that this reduction would not take place until after 2022."

John Foster, an emeritus social sciences professor at Paisley University who convened the study, argued that there would be less than 1000 jobs lost in the communities that surround the Clyde bases. He said that new jobs would be created at Faslane by the introduction of Astute-class submarines, which do not carry nuclear weapons.

Dire predictions of job losses assume that the Government would close the entire Faslane base which was "highly implausible", he said. "The SNP Government has made it clear that it would keep Faslane open were Trident to be cancelled."

But Baillie defended her figures as defence experts had told her that the entire base hinged on Trident.

It was "too simplistic" to just focus on the 520 jobs that directly relied on Trident, she said. An independent Scotland would not be able to maintain a fleet of submarines. "Whatever people think about nuclear weapons, there is a responsibility to think about the jobs," Baillie argued.

The SNP MSP, Bill Kidd, said: "Trident is, in reality, a jobs-destroyer, and attempts to justify the presence of weapons of mass destruction on the Clyde in terms of jobs is the worst kind of nonsense, as Jackie Baillie knows only too well."