The makers of a new pro-life movie starring Jon Voight have accused Facebook of blocking promotional ads. 

Roe v. Wade is a dramatisation of the historic court battle that resulted in the legalisation of abortion in the US and also stars Stacey Dash of Clueless fame. 

Breitbart reports that filmmakers Nick Loeb and Cathy Allyn attempted to post an advert on Facebook linking to an article by the Hollywood Reporter on the movie and featuring the hashtag #BringRoevWadeToLife.

The filmmakers say they tried to boost the post - a paid tool that Facebook offers to reach more users - but the ad was reportedly blocked because it contravened the social media giant's new rules on 'issues of national importance'. 

Loeb and Allyn told Breitbart that they had received an email from Facebook telling them that the ad was not approved 'because it doesn't comply with our Advertising Policies' and that they could re-submit an edited version for consideration. 

Facebook said in a statement to Breitbart that the ad 'involves an advocacy issue 'under our issues of national importance'. 

The new rules apply to ads of a political nature and require additional information from Facebook users to verify their identification as well as who paid for the ads before they are approved.  

'Transparency continues to be a major priority for us in order to prevent election interference, so we are taking a broad approach to start as we roll out this policy further,' Facebook's statement read. 

Last year, the makers of another pro-life movie, Gosnell, also claimed that their boosted posts had been blocked by Facebook. 

The movie starred Dean Cain and told the story of real-life late term abortionist Kermit Gosnell who was sentenced to life without parole over the deaths of three babies born alive during abortion procedures at his Philadelphia clinic. 

At the time, producer Phelim McAleer accused Facebook of having a liberal bias against pro-lifers. 

'The Silicon establishment do not want this story told,' McAleer said.

'They [Facebook] simply state it's not been approved and to check their standards, but it does not give you a specific reason why this post could not be promoted at all to a wider audience.

'It's clear it is the pro-life audience that they don't want to encourage or provide content to. They really hate anyone who doesn't subscribe to the liberal world view.'