The alarm has been raised after demand for emergency accommodation jumped by as much as 94 per cent in Glasgow and 38 per cent in Edinburgh compared to last year.
Glasgow City Mission reported being full on 32 nights in 2015/16 – something that never happened in previous years. An average of 33 people used the shelter on any single night, compared to just 17 last winter.
Meanwhile, the Bethany Christian Trust in Edinburgh has seen demand for beds rise by 131 per cent since 2013, with an average of 48 people taking refuge on any night during winter 2015/16.
More than 600 people are known to sleep on Scotland’s street every night, but the new figures have sparked concern that the number of homeless Scots could be increasing.
Now the charities say tackling the problem must be a priority for the next parliament, in order to avoid a “devastating and avoidable homelessness crisis”.
Iain Gordon, chief executive of Bethany Christian Trust, said: “A great deal of progress has already been made in tackling homelessness in Scotland.
“However, the combination of a shortage of affordable homes, welfare reform and budget pressures mean that homelessness is still a very pressing issue in our country.
“I appeal to all political parties to use the new powers coming to the Scottish government to maximise the benefits of devolution so people don’t have to face a devastating and avoidable homelessness crisis.”
Grant Campbell, chief executive of Glasgow City Mission, said: “We’ve witnessed a significant rise in demand for the Glasgow winter night shelter, and behind every statistic is a person, a mother, father, son or daughter.
“We believe there is a significant opportunity with the upcoming elections, with public demand and political will for Holyrood, local authorities and service providers to work collaboratively to put an end to homelessness.
“This is not just an issue around housing, but health also, and we should assume and be prepared for solutions which require a brave, determined and concerted effort by all.”
The charity Crisis has set out a series of recommendations for the next government to follow after next week’s election.
Jon Sparkes, chief executive of Crisis, said: “Scotland has blazed a trail in the fight against homelessness, yet these startling figures cannot be ignored.
“We know from official figures that around 660 people sleep rough on Scotland’s streets on any typical night, and we are concerned that the situation may have worsened in recent months.
“There is no room for complacency, which is why we are calling for decisive action from the next Scottish government to help all homeless people.
“Our manifesto already has cross-party support, and we welcome the ongoing commitment to tackle the devastating injustice of homelessness.
“Yet we need this to be followed up with action, and we look forward to working with all parties to continue the fight after the election in May.”