The workers, who are based across the UK, have accused the organisation’s management of attempting to impose a real terms pay cut on its staff.

The strike action will begin on Monday 5 December, ending on Sunday 18 December, after staff returned an 85% vote in favour of industrial action, Unite said.

According to the union, management at Shelter has sought to impose a 3% pay increase on staff, describing it as “a huge real terms pay cut” with the true inflation rate (RPI) currently standing at 12.6%.

Unite general secretary Sharon Graham said: “Shelter’s workers are absolutely dedicated to the organisation but they have been forced to take strike action as management refused to listen and understand their financial plight. Rather than sit on ever expanding reserves, Shelter should be paying its workers a fair pay rise.

“Unite does what it says on the trade union tin and always prioritises the jobs, pay and conditions of its members, the workers at Shelter will receive the union’s unstinting support.”

Commentating on the decision to go on strikes one member of Shelter’s staff told the union: “The work we undertake, particularly in frontline services, is so valuable and clients depend on our teams. But that shouldn’t mean they have to sacrifice a decent and dignified living because the work they are drawn to is in this sector. At the very base level, absolute bare minimum, those working for a housing charity shouldn’t be experiencing housing insecurity as a result of being unable to pay rent.”

Another added: “I really care about the work and I think it’s recognised that I work hard - but I don’t feel right now my employer cares about me. I’m a single parent. I’m now in overdraft every month, I go around switching my lights off, I have turned my boiler down, I get stressed when the kids school wants me to pay for another school trip. The best acknowledgement my employer can give me for all my hard work is decent pay.”

Unite regional officer Peter Storey said: “Strike action will inevitably cause substantial disruption to the services that Shelter provides. However, the organisation has created this dispute through the arrogant and high-handed manner in which it has treated its loyal workers.”