In numerous conversations with ministers since the comprehensive spending review, I was assured that any review of the UK's solar photovoltaic (PV) feed-in tariffs before April 2012 would not happen unless installations exceeded a certain published level and would exclude urban solar PV, tackling only the green field solar farms. The government has not only betrayed those assurances, but today proposes feed-in tariff rates that will ensure the UK PV industry stalls.

More than 40 countries have chosen to build their renewable energy industries via a feed-in tariff: a levy on energy bills that reduces over time, on particular dates flagged to the market well in advance, as costs fall in the industry created by the tariff. The details of the UK's "ambush" review of solar are arcane, but the core problem is that at the rates the government proposes for every installation above a mere 50 kilowatts, those once considering solar roofs will be put off en masse.

Property developers and companies whose premises have large roofs will take a quick look at the diminished returns and say no. Many of the energy co-operatives being set up around the country will no longer be able to persuade enough citizens to go ahead. Solar investment funds being set up will hand money back to investors – they had already started to do so even once the risk of today's announcement had become clear a few weeks ago.

In announcing this sabotage, ministers make a mockery of their own supposed core objectives: local empowerment within a "big society"; massive job creation – via a green industrial revolution – to counter austerity-related job losses; desire to be the greenest government ever; tackling global warming, and so on. Rather than putting them on track to fulfil their rhetoric, the proposed tariffs add to the growing evidence that this will be not the greenest but the meanest government ever.

The total cost of the PV tariff to date has been less than 1p a month on domestic bills and the total feed-in tariff spend is running way below the government's projections. Meanwhile thousands of new green jobs had been created, and the Treasury had already begun benefiting from the increased tax and national insurance income. All of that has been debilitated at a stroke.

No renewables company or investor can easily trust this government again after this U-turn by ministers. They were so quick in opposition to call for a more ambitious feed-in tariff. They were so ready with empty promises in the early months of their term of office. How can they expect us ever to trust them again now?

Moreover, they do all this at the time of both the Fukishima nuclear disaster and profound instability in the Middle East. The inevitable slowing in plans for a UK nuclear renaissance and the potential end of an affordable oil supply mean that the UK needs fast-growing domestic renewable energy industries more than ever. In setting us back at such a time, I believe the government is now guilty of a betrayal of the UK's national security interests.

• Jeremy Leggett is the founder and chairman of Solarcentury