SCOTTISH Labour has stepped up its bid to make housing a key election battleground after promising to build 60,000 affordable homes if it wins power in May's Holyrood poll.

The party is also considering setting a separate target for social housing, in a move senior MSPs believe would highlight failings by the SNP government.

Ken Macintosh, Scottish Labour's communities spokesman, confirmed the ambitious plan after repeated clashes between his party and the SNP over housing.

Earlier this week, Kezia Dugdale, the Scottish Labour leader, unveiled a plan to hand first time buyers up to £3000 to help them get on the housing ladder.

The policy, her first major election pledge, was dismissed by the SNP as Nicola Sturgeon challenged Labour to match her plan to build 50,000 affordable homes over the next five years.

In a letter to the First Minister, Mr Macintosh said Labour would deliver the 12,000 affordable homes per year that a consortium of organisations, including Shelter, the Scottish Federation of Housing Associations and the Chartered Institute of Housing, says is required to ease the country's housing crisis.

"If elected to government in May, Scottish Labour have promised as a minimum to meet this identified affordable housing need," he wrote.

Referring to exchanges during First Minister's Question, he said: "The SNP mask slipped when the First Minister, inadvertently or not, admitted that Scotland is facing a housing crisis.

"At last the SNP or the First Minister at least, seem to be accepting they have some responsibility for this crisis.

"They could begin by matching Labour’s commitment to addressing housing need, rather than setting targets which once again fall short."

Senior MSPs will meet next week to discuss whether a separate target for socially rented housing should also be set out in Labour's manifesto.

"Social housing" is secure, low rent accommodation provided by councils or social landlords, usually housing associations.

The term "affordable housing" includes social housing but also properties let at mid market rents or sold under subsidised shared equity or other low-cost home ownership schemes.

At the last election in 2011 the SNP promised to build 30,000 socially rented houses but quietly watered down the pledge, changing the target to affordable homes.

One Labour source said: "There is an important distinction to be made.

"Affordable housing is not affordable for many people and the SNP have failed to deliver their original promise.

"We want a clearer emphasis on social housing."

Of the 30,000 affordable homes built since 2011, around 20,000 have been for social rent. Housing bodies have been told the SNP wants to build 35,000 socially rented houses as part of its promised 50,000 affordable homes by 2021.

Around 150,000 households in Scotland are on council waiting lists for accommodation.

Mary Taylor, chief executive of the Scottish Federation of Housing Associations, said "the bulk" of new affordable housing should be for social rent.

She added: "While we believe that there is room, and indeed need, for a range of solutions to tackle the housing crisis, it is vital that the majority of affordable homes are for social rent.

"However, there is a real danger that if housing grant rates are not increased, this will not happen.

"Housing has to be affordable to people on low to moderate incomes, and this can’t be realised without increasing grant rates."

SNP MSP Clare Adamson dismissed Labour's plan.

She said: "Given that both Labour’s leader and deputy leader repeatedly failed to give any commitment on homebuilding this week, most people will see this panicked announcement for what it is.

"The SNP government has exceeded its target to build 30,000 affordable homes this term, including over 6000 council houses compared to Labour’s paltry six in office.

"If re-elected, we plan to go further and have committed to at least 50,000 new affordable homes in the next term."