The website and Twitter accounts of high-ranking members of Britain First have been hacked and replaced with a message threatening to bomb a planned march on 3 June.
The name of Golding’s Twitter account has been changed to “racist f****** chav” and his personal details, including his home address, have been posted online.
Similarly the text of Fransen’s website – which detailed her background, contact details and involvement with the group – have been replaced with a plain text warning that “several bombs will detonate and those who will march be dead (sic)”.
It ordered the group to “stop being racist to Muslims” and warned “whoever goes to the march will die”.
The person behind the threat is currently unknown.
The controversial group, which has been banned from entering any mosque in the country, is planning a march through Birmingham on 3 June to protest against what it calls the “Islamification of Britain”.
Earlier this week Golding, Fransen, and former English Defence League (EDL) leader Tommy Robinson filmed themselves walking down a predominantly Muslim area of Birmingham waving large white crosses.
They claimed they were attacked by a group of “aggressive” Muslim men but other footage from the scene showed several Muslim men, returning from a volunteering mission in Iraq, attempting to engage Robinson in debate before he was bundled into the van by the group.
The group has sought to capitalise on last month’s Westminster terror attack when Khalid Masood ploughed a car into pedestrians on Westminster Bridge before stabbing a police officer and attempting to enter the Houses of Parliament.
The 52-year-old, who was shot dead at the scene, was a Muslim convert had been living in Birmingham before his death.
A similar march by the EDL in Birmingham at the weekend ended with a picture of anti-fascist protester smiling in the face of EDL leader Paul Crossland going viral.
Saffiyah Khan later said she was not intimidated and instead all she saw “was an angry man having a rant”.
A spokesman for the Metropolitan Police told The Independent the matter had been reported and was currently under investigation.
When The Independent contacted Britain First they said they were aware of it but refused to comment any further.