TORY plans to impose a new levy on those leaving university to pay for a boost in college funding would cost graduates £6,000 each, according to opponents.

The Scottish Tories have backed a 'graduate contribution' and said the move would help boost other further education establishments, addressing a skills gap and bringing benefits for the economy.

Scottish Labour said the party's claim that it would spend £100 million on colleges and skills means that graduates would be left with bills of several thousand pounds with cash not becoming available for several years. Independent Holyrood researchers said the £6,000 figure would be necessary to make up the level of cash the Tories promised.

Labour believe that in order to set up a levy on graduates, legislation would need to be passed, with another four years before any money is seen. The party has said it would be 2021 at the earliest before the policy generated any revenue.

Scottish Labour Opportunity spokesperson Iain Gray said his party backed free tuition and added: "To make the sums add up for their empty promises they would charge Scottish students an eye-watering £6,000. For all the clever spin Ruth Davidson is just another Tory."

The SNP has written the Scottish Tory leader Ruth Davidson to seek further clarification on her proposals. SNP MSP Gordon MacDonald, whose Edinburgh constituency includes Heriot Watt University, said proposals to end free higher education in Scotland were "deeply troubling".

He added: "Not only are these plans a threat to opportunity and ambition for young people in Scotland, they’re badly thought through – with no detail about which students would have to pay to learn, or when or how they would be charged.

"It seems as though the Tories have just rehashed an old Labour policy in a potentially reckless move which could price some aspiring university applicants out of the market – all for the sake of raising a quick buck."

The National Union of Students said the Conservatives' plans would "saddle students with thousands of pounds extra debt, with no additional support in return."

A spokesman for the Scottish Conservatives defended the plan. He said: "Given the scale of SNP cuts to further education, we believe colleges need extra funding so we can boost our skills base and grow the economy in Scotland.

"As has been the case for some years, we also believe that a graduate contribution can help to find resources. We will set out plans to improve education in our manifesto and they will be fully costed. That stands in marked contrast to Scottish Labour which is quite cynically conjuring new money out of thin air."