The Islamic State terror group is planning a massive attack in the United Kingdom, and the current level of threat posed by its homegrown members is the highest in over 30 years, according to the head of Britain’s domestic security service.

At an annual defense and security conference, MI5 Director-General Andrew Parker said that over the past 12 months, his agency has thwarted six IS terror plots in Britain and seven abroad.

Parker added that currently 80 percent of the agency’s 4,000-strong members were focused on uncovering and stopping terror attacks, with an increasing number of those linked to IS.

The threat emanating from al-Qaeda was also high, with the terror group also planning large terror attacks on UK soil.

Andrew Parker (Courtesy)

Andrew Parker (Courtesy)

“More than 750 extremists from this country have traveled to Syria, and the growth in the threat shows no sign of abating,” Parker said, according to The Telegraph.

“We are seeing plots against the UK directed by terrorists in Syria; enabled through contacts with terrorists in Syria; and inspired online by ISIL’s sophisticated exploitation of technology,” he said, using another acronym for the terror group.

“On top of that, in a range of attacks in Europe and elsewhere, this year we have seen greater ambition for mass casualty attacks. All of this means that the threat we are facing today is on a scale and at a tempo that I have not seen before in my career,” added Parker, who has been in intelligence for 32 years.

According to the intelligence chief, the online threat that IS and other terror groups represent has prompted intelligence agencies to upgrade their “toolboxes,” including using computer hacks to fight back.

“This includes the ability to conduct operations online and to mount IT attacks (known as equipment interference), under a warrant authorized by the Home Secretary, against terrorist networks, so that we can access their communications,” he said.

“We use these tools within a framework of strict safeguards and rigorous oversight, but without them we would not be able to keep the country safe,” he went on.

The UK’s perhaps most infamous homegrown IS terrorist is Mohammed Emzawi, aka “Jihadi John,” who has appeared in several gruesome beheading videos posted by the terror group.