Scotland's ambitious target to meet the country's energy needs from green power is set to be missed, a study warns today.

Industry body Scottish Renewables said the Scottish government's goal would not be achieved by the 2020 deadline without further investment from Westminster.

In an urgent plea to UK ministers, it warned uncertainty over the government's plans could soon kill off major schemes vital to meeting the target.

The new study suggests that on current trends renewables will generate the equivalent of 87 per cent of Scotland's energy needs by the end of the decade.

It comes after a leaked letter from UK energy secretary Amber Rudd revealed the UK as a whole was unlikely to meet it EU obligation to generate 15 per cent of its power from renewables by 2020.

According to reports, the minister suggested funding renewable schemes in other EU countries as a last resort measure to meet the target.

Fergus Ewing, the Scottish energy minister, reacted angrily, accusing the UK Government of "attacking" the renewables sector, which has a proportionately bigger presence in Scotland than south of the Border.

The UK Government has already cut subsidies for renewables sector.

Niall Stuart, the chief executive of Scottish Renewables said: "The 100 per cent target has provided a powerful focus.

"However, current projections show that we're not going to meet it unless we get more projects going ahead between now and 2020.

"There are consented schemes onshore and offshore that could get us there, but they can only go ahead if they are allocated a long term contract for their power."

An auction for contracts, which was expected this autumn, has been postponed, damaging investment in the industry.

Unless they are signed in the spring, major developments proposed for the Western Isles and Shetland will be "fatally undermined," warned Mr Stuart.

"Essentially it is this simple - if we get an allocation round next spring and enough Scottish projects are successful we can still hit the target," he added.

His comments were echoed by Lang Banks, director of WWF Scotland, who said the industry "urgently needs certainty" from the UK Government about future funding.

The Scottish Government wants the equivalent of all the country's energy needs to be generated from green sources by 2020.

The goal set by the then-first minister Alex Salmond in 2011 after existing targets were exceeded.

Just under half of Scotland's energy needs were met by renewables last year.

Mr Ewing said: "Recent announcements by the UK Government represent an attack on the renewables sector, creating huge uncertainty for investors, developers and communities, and undermining Scotland’s ability to fulfil its renewable energy potential.

"I share Scottish Renewables’ concerns that the damaging and premature cuts to support for renewable energy being driven through by the UK Government will hamper future progress."

He added: "I am dismayed by the reports that the UK Energy Secretary appears to have admitted privately to her ministerial colleagues that the UK Government will miss its 2020 renewables target.

"We were led to believe the decision to cut subsidies for renewables was based on targets being met but now we learn that the UK is expected to miss its 15 per cent energy from renewables target by a wide margin.

"The UK Government continues to dither on a meaningful approach to renewables."

Labour MSP Sarah Boyack agreed UK Government policy was deterring investment.

But she added: "This is also a wake-up call for the SNP.

"Jobs and investment are at stake and they must make it their business to keep their promise to meet the 100 per cent renewable electricity target by 2020."

In further sign of the pressures on the renewables sector, Mr Ewing faced calls to spend a £10million prize pot earmarked for the Saltire Prize, the marine power contest launched by Mr Salmond in 2008, immediately in a bid to help the struggling industry.

Orkney MSP Liam McArthur accused the Scottish Government of choosing to "save the reputation of the former first minister" by continuing to support the prize, which is due to be awarded in 2017.

He challenged the minister after The Herald revealed new rules for the contest will not be drawn up until next year.

It emerged earlier this year that none of the remaining competitors is able to meet the original qualifying criteria.