ISTANBUL, May 15 (Reuters) - A group of Turkish real estate firms said on Tuesday that home buyers would get a 20 percent discount on house prices and that down payments for mortgages would be reduced to 5 percent as part of a month-long drive to revive sagging property market.

Forty-one companies, including housing companies and construction firms, will participate in the initiative, which comes as the Turkish government tries to address a recent sharp decline in house sales in the run-up to elections on June 24.

Last week two state-owned lenders lowered their mortgage rates after President Tayyip Erdogan urged local banks to help boost the real estate sector, one of the pillars of Turkey’s economy. The government also announced a 10 percent cut in value added tax for certain buyers.

The one-month initiative is expected to generate around 3 billion liras ($678 million) worth of sales, Nazmi Durbakayim, chairman of the Istanbul Construction Companies Association (INDER) said in a news conference with the Real Estate Investment Companies Association (GYODER) and the Housing Developers Association (KONUTDER).

Their joint measures will be in effect until June 15, the three organisations said.

Turkey has around 2 million unsold houses, according to sector officials, a backlog worth three times average annual new housing sales. In March home sales fell 14 percent and mortgage sales declined 35 percent compared to a year earlier, official data showed.

“The measures ... have started to bring a breath of fresh air to real estate,” Konutder head Ziya Altan Elmas said in a statement speaking in the name of all three associations.

“We expect the housing sales to revive in the coming days and we will finish 2018 with record sales.”

Turkey’s lira slid to a record low and bond yields briefly touched their highest in at least eight years on Tuesday, after Erdogan said he plans to take greater control of the economy after elections next month.

Turkey has called snap presidential and parliamentary elections for June 24 and polls show Erdogan as the strongest candidate to win the presidential vote. ($1 = 4.4235 liras) (Reporting by Ceyda Caglayan Writing by Ezgi Erkoyun Editing by Raissa Kasolowsky)