OTTAWA -- A group of veterans vowed to keep fighting the federal government Monday after the B.C. Court of Appeal rejected their landmark legal effort to win back lifelong disability pensions for former members of the military.

A three-judge Appeal Court panel threw out the five-year-old lawsuit alleging the government discriminated against disabled veterans when it changed the way those injured in the line of service are compensated.

Chief among the most controversial changes, implemented in 2006, was replacing lifelong disability pensions with a lump-sum payment, career training and targeted income support -- a regime known as the New Veterans Charter.

The six veterans involved in the lawsuit claimed the charter provided veterans with about 40 per cent less over a lifetime than the previous pensions, which they want re-instated or replaced with a true equivalent.

The suit -- which argued that Ottawa is honour-bound to uphold a 1917 "social covenant" from then-prime minister Robert Borden that the government would always look after those in uniform -- has no chance of success, the Court of Appeal ruled.

"The idea that inspirational statements by a prime minister containing vague assurances could bind the government of Canada to a specific legislative regime in perpetuity does not, in any way, conform with the country's constitutional norms," Justice Harvey Groberman wrote on behalf of the panel.

The judgment, which did not look at whether disabled veterans were adequately compensated, also dismissed the claim that the charter rights of vets had been violated.

Monday's ruling reverses a 2014 decision by the B.C. Supreme Court allowing the case to proceed to trial -- a decision federal government subsequently appealed.

Retired major Mark Campbell, one of the six veterans involved in the case, made his feelings clear Monday during a news conference in Vancouver.

"In effect, by saying that there is no sacred obligation, there is no social covenant embedded in the law, what that tells us is that no one has our backs," Campbell said alongside his fellow plaintiffs.

"From boot camp down the line, you're told, 'Don't worry. If you're injured on service, the government will have your back.' We find out today there is no law saying this is the case."

Campbell and the others admitted that they were unsure exactly how to proceed, including whether to seek leave to appeal to the Supreme Court. But they promised to keep up the fight, even if it means focusing on advocacy and political action as opposed to court action.

"We need the veterans out there to know that we are going to keep fighting for them and not to lose any hope," said retired corporal Aaron Bedard. "We're not going anywhere."

While Monday's ruling represents a win for the federal government, it could actually represent a double-edged sword for Prime Minister Justin Trudeau and the Liberals.

That's because the Liberals promised to reinstate lifelong pensions. Indeed, Trudeau even campaigned with Equitas members prior to the 2015 election. And yet his government continued to fight the court case after coming to power, and has yet to reinstate the pensions as promised.

Veterans Affairs Minister Seamus O'Regan was sombre Monday as he promised to unveil the government's new pension plan by the end of the year.

"We want to do right by those ill and injured veterans to make sure they have financial security," O'Regan said outside the Commons.

"Regardless of the results of the case, the outcome of the case today, that was our determination. That was and remains our goal. We will have a pension for life option ready to present to veterans."

But many veterans, including members of the Equitas lawsuit, fear the government plans to keep the lump-sum payment in place and merely spread it out over several years.

Asked whether veterans would be satisfied with the new plan, O'Regan said: "One thing that I've learned in a short amount of time is that it is absolutely impossible to make everybody happy.

"But we believe, and what keeps us working every day and through weekends in these past few weeks is we believe that we will do right by our veterans with what we are working on."

-- With reporting by Geordon Omand in Vancouver