 SUPPORTERS of Scotland s burgeoning solar power industry, estimated to be worth ?50 million to the Scottish economy, have warned that the UK Government s threat to slash consumer subsidies for solar projects by 50% threatens  thousands of jobs  in the emerging sector.  Scotland has 140 companies listed as supplying solar power equipment. Industry figures  are warning of mass lay-offs if the planned cut drives down demand and companies go out of business. Daniel Borisewitz of industry group Scottish Renewables told the Sunday Herald that the move would have  a real impact on the feasibility and economic viability of businesses supplying and installing while also damaging consumer and investor confidence in renewable energy incentive schemes.  The Department of Energy &amp; Climate Change s (DECC)  review consultation  for solar feed-in tariffs (FIT), announced  last month, proposes to halve subsidies for solar projects between 1kW and 50kW, with a further FIT cut for buildings that are not up to the required energy-efficiency ratings. The changes come into effect from December 12, four months earlier than previously announced.  according to the DECC the latter measure could rule out up to 86% of households in the UK which do not meet the minimum efficiency requirement.  andrew Lyle, managing director of Edinburgh-based Locogen, told the Sunday Herald:  It s an absolute nightmare. People are rammed with work between now and December, and it s going to be dead after that.  The issue is threatening to split the Coalition Government after reports last week that Liberal Democrat politicians were organising against the proposed move.  The proposed cuts have already provoked a furious reaction from SNP, Labour and Green politicians, environmentalists and industry figures.  Last Friday,  a  day of action  or  mass lobby of parliament  to urge MPs to block Government plans to cut the feed-in tariff was announced for December 12, to rally political opposition to the early cut-off date.  The consultation deadline, originally planned for april 2012, has also been brought forward to December, leading to complaints that the sector has had too little time to adjust business plans. any FIT application now received on or after December 12 will be affected by the new proposals.  Under the new regime, promised rates of return for solar power users are likely to drop from 11% down to 4.5-5% in the domestic sector, 11% to 3% in the social housing sector, from 15% to 7% in the small commercial sector and from 15% to 8% in the larger commercial se 