A group of Canadian scientists is calling on Elections Canada to provide further clarity on how to communicate the effects of climate change during the federal election campaign.

More than 300 scientists added their name to an open letter sent out Thursday morning, directed at Elections Canada Chief Electoral Officer Stéphane Perrault, stating that the organization’s application of the Elections Act is cause for concern.

"While you have clarified the Elections Canada rules, application of the rules in this case is still problematic," the letter states.

Perrault issued a statement on Tuesday after news broke this week that there was confusion around whether climate change was considered an "issue" during the election period, thereby making it partisan.

This stems from comments made by People’s Party of Canada Leader Maxime Bernier, who expressed doubts about the legitimacy of climate change, making it a platform talking point rather than objective fact.

The Elections Act says that advertising by third parties can be considered partisan if it promotes or disputes an issue raised by any party or candidate during the campaign period, even without naming that party or candidate. If the ad campaign on that issue costs $500 or more, the third party has to register as such with Elections Canada. Election advertising rules came into effect on June 30.

The letter from scientists goes on to say that the interpretation of these rules infers climate change "as something about which there is doubt," yet Elections Canada “does not enforce rules around registration on many other issues upon which there is scientific consensus."

The group lists the health impacts of tobacco as an example.

In an emailed response to CTVNews.ca, Katie Gibbs, the executive director of Evidence For Democracy, which published the open letter under its banner, said "Our concern is over the incredibly broad way that Elections Canada is interpreting an election 'issue' under the act and that they are not distinguishing between facts and opinion in that consideration. As well as the lack of clarity around what threshold makes something an 'issue.' If a candidate tweets about it, is it an issue?"

In response, Perrault reiterated his remarks from earlier this week that the Elections Act doesn’t prevent any one group from speaking about climate change. Only when individuals or organizations reach that $500 advertising spending threshold, will they have to register with Elections Canada.

He also stated that Elections Canada doesn’t dictate what an “issue” is during a campaign season or identify fact from opinion.

"The law, as currently written, ensures that ‘issues’ are determined by candidates and political parties, and not restricted by anyone, including Elections Canada. The Act also ensures that there is transparency about who is paying for advertising about those issues," said Perrault in an email to CTVNews.ca.

With files from The Canadian Press