An appeal by Prime Minister Justin Trudeau to Canadians living abroad for donations to the Liberal party has struck a sour note with disenfranchised long-term expats.

The cash solicitation on Trudeau's Facebook page calls on Canadians living abroad to be part of "Canada's most open and progressive movement," and says under a picture of the prime minister that "your donations help fuel our party."

Various comments reflect the displeasure of those unable to vote in federal elections because of a law — only enforced by the previous Conservative government under Stephen Harper — that strips voting rights from those who have lived outside Canada for more than five years.

"Asking for my donation after removing my right to vote is just offensive," wrote Ian Doig, who lives in Houston.

Another commenter, Angus McGillicuddy, offered a similar sentiment.

"Not going to waste my money until our constitutionally guaranteed right to vote is restored," McGillicuddy said.

You have some gall asking for expats' money when you've done nothing to restore our vote, despite promises during the election by your members that you would rectify the situation - Kate Tsoukalas

The disenfranchising of an estimated 1.4 million long-term expats has been a running legal battle since Canadians abroad found they could not vote in the 2011 election. While the rules were first enacted in 1993, they had not been enforced until then.

Two Canadians living in the U.S. went to court to argue the relevant parts of the Canada Elections Act were unconstitutional.

In May 2014, an Ontario Superior Court justice ruled in their favour. However, the Harper government appealed on the grounds that it would be unfair to resident Canadians to allow those abroad to elect lawmakers. Ontario's top court sided with the government. The Supreme Court of Canada is slated to hear the expats' appeal of that decision in February.

"Canadians living abroad should be able to vote with more than their pocketbooks," Gillian Frank, one of those who launched the constitutional challenge, told The Canadian Press.

NDP bill would restore expat votes

The voting issue became a flashpoint for many expat Canadians during last year's election that propelled Trudeau to office. He has since indicated a willingness to review the ban, and a spokesman has said the government believes "more Canadians should have the right to vote, not the opposite."

However, nothing has changed and the Supreme Court case remains pending.

"You have some gall asking for expats' money when you've done nothing to restore our vote, despite promises during the election by your members that you would rectify the situation," Kate Tsoukalas wrote in a post.

In the interim, the New Democrats put forward a private member's bill in June that would enfranchise the expats as an "act of fairness."

"The prime minister should support the Canadian diaspora by endorsing the proposed legislation that restores our right to vote and by instructing the attorney general not to challenge our Supreme Court case this coming February," Frank said.

Requests for comment from Trudeau received no immediate response Tuesday.