Will Bernie Sanders write-in votes lose the election for Hillary Clinton?

Democrats in Bernie Sanders' stomping ground of Vermont have warned his supporters not to "waste" their votes by writing in their support for him.

The former presidential hopeful has backed his fellow Democrat Hillary Clinton since she beat him in the primaries, but some of his supporters are not convinced – and are planning to "write-in" their votes for him.

A write-in candidate is a someone in an election whose name does not appear on the ballot, but whom people may vote for anyway by writing in their name.

Democrats in Vermont are worried the ongoing support for the popular senator will be a setback for Clinton.

"Hillary Clinton is the candidate who will actually push for the agenda that Bernie Sanders fought for," Christina Amestoy of the Vermont Democratic Party told NBC News.

"Choosing not to vote for Hillary Clinton is choosing to either abstain or maybe even cast a vote for Donald Trump."

Sanders himself has also encouraged his supporters to vote for the Democrat candidate, rather than handing votes over to Trump.

But despite the warnings, there are expected to be more write-in votes than usual, from both Democrats and Republicans, with many of the former disappointed that Sanders was not chosen as the candidate, and many Republican voters upset Donald Trump is representing the GOP.

Unpopular

In fact, with Clinton and Trump set to go down as two of the least popular presidential nominees in recent history, officials in some states have been warned there may be extra work to do in terms of vote counting.

Vermont Secretary of State Jim Condos told the news service write-ins votes would be counted and the results released about a week after the election.

"We're cautioning the clerks and election officials on the local level that there may be more [write-in votes] than usual this year," he said.

But the lack of popularity of both the Democrat and GOP nominees has not had quite the positive impact on Libertarian candidate Gary Johnson or Green Jill Stein, as some suspected at the beginning of the election cycle, despite Johnson describing his support as "phenomenal" in a recent interview.