* State to invest 20 bln euros over 5 years * Target of 33,000 homes built per year * New vacant property, rezoning taxes planned (Adds quote from PM, criticism from opposition) DUBLIN, Sept 2 (Reuters) - The Irish government on Thursday announced a multibillion euro plan to tackle the country’s housing crisis, which has become a huge political issue as voters fear an entire generation may be frozen out of home ownership. The plan, which includes a guarantee of 20 billion euros ($24 billion) of state funding over the first five years, is aimed at increasing homebuilding to an average of 33,000 units per year by 2030 from around 20,000 last year. Ireland has fallen well short of meeting housing demand each year since an enormous property crash over a decade ago brought the construction sector to its knees, bankrupting many developers and prompting construction workers to emigrate or retrain. The years-long mismatch between low supply and high demand has been compounded by two shutdowns of the construction sector in the past 18 months to slow the spread of COVID-19. The resulting stalling in the building of new homes has contributed to house prices rising to near all-time highs and rents increasing from already record levels. Highly paid young professionals say they are unable to consider property ownership and huge queues bidding outside rental properties have become a staple of television news. The issue has helped fuel the rise of the left-wing nationalists Sinn Fein and has contributed to a collapse in support for the party of prime minister Micheal Martin. “If we do not recognise the scale of the challenge and respond to it in time it has the potential to be profoundly destabilising for our country,” Martin said at the launch. Measures to help boost supply include a new tax on vacant sites, the purchase and resale of vacant properties by the state and an increase in the average number of social homes built by the state to 9,500 per year by 2030. The government also plans to introduce a “land-value sharing” tax so that part of the rise in the value of development land following the re-zoning of land for housing is shared with the state. It did not say how large the tax would be. To address an affordability shortfall, the government will use a mixture of the direct provision of social homes and schemes for affordable and cost-rental housing. The opposition Sinn Fein party said the plan was overly-reliant on private sector output, with party leader Mary Lou McDonald calling for a doubling of direct government spending on housing from what is proposed in the plan. “It’s a blueprint for more of the same... failed policies that created this crisis in the first place,” she said. $1 = 0.8438 euros Reporting by Conor Humphries Editing by Hugh Lawson and Mark Potter Our Standards: The Thomson Reuters Trust Principles.