Boris Johnson’s government must end the “outrageous” inequality in pension payments for Gurkhas who fought with the British Army, Labour has said.

       Three Gurkha veterans are on the fifth day of a hunger strike protest outside Downing Street over the government’s failure to provide them with a full Armed Forces pension.

       Stephen Morgan, Labour’s shadow defence minister, said on Wednesday he was writing to defence secretary Ben Wallace to demand immediate action on pension parity for the Nepalese-born soldiers.

       “I’m really concerned about this issue – Gurkhas have served our country for 200 years,” the Labour MP told Sky News. “It’s outrageous that the inequality continues. The government promised two years ago to do something about this. We’re calling for action now.”

       The shadow minister added: “Gurkhas doing this protest right now should now I’m supporting them every step of the way. I’ll be writing to Ben Wallace today to end this injustice.”

       Asked about the plight of the three men staging a hunger strike, who have said they are willing to die in their fight for equality, Mr Morgan added: “It shows a huge stain on society for all of us.”

       The hunger strikers on Whitehall are campaigning for equal pension payments for Gurkha veterans who retired before 1997 and are still not eligible for a full pension.

       Serving Gurkhas and all those who retired after 1 July 1997 were allowed to transfer to the Armed Forces Pension Scheme – but those who retired before that date remain part of the old Gurkha Pension Scheme, worth between a third to half of a full Army pension.

       Dhan Gurung, of the three hunger strikers who has been sitting across the road from No 10, told Sky News on Tuesday he was prepared to die. “Our ancestors gave their lives in order to save Great Britain and now we are fighting for equal rights … Hunger until the death.”

       Gurkha veteran Nims Purja called on Mr Johnson to force a change in the rules. “I think the government has respect for the Gurkhas. But there’s a difference between respect in the form of words and in practice as well,” he said.

       Mr Purja added: “I would humbly request the UK government, the prime minister, to look into this matter seriously.”

       A spokesperson for the Ministry of Defence said: “We greatly value the huge contribution Gurkhas make to the British Army and ensure they are supported with a generous pension and medical care during retirement in Nepal.

       “We are committed to ensuring the Gurkha Pension Scheme is sustainable and fair alongside other UK public sector pensions.”