Hackers affiliated with the Anonymous hacktivist collective have vowed to relaunch cyber-operations against US presidential candidate Donald Trump from 1 April. They threaten to 'dismantle his campaign' by taking his election websites offline in a large-scale and orchestrated distributed denial-of-service (DDoS) attack.

In December 2015, Anonymous officially 'declared war' on Trump after a radical speech in which he said Muslims should be banned from entering the United States. The operation at the time resulted in a number of websites being targeted by hackers, but failed to have lasting impact.

A new video statement has been posted to YouTube which claims the 'loyalists and veterans' of Anonymous have decided to ramp up cyber-operations against Trump – dubbed #OpTrump – on a far larger scale than ever before.

"Dear Donald Trump, we have been watching you for a long time and what we see is deeply disturbing. Your inconsistent and hateful campaign has not only shocked the United States of America [but] you have shocked the entire planet with your appalling actions and ideas. You say what your audience wants to hear but in reality you don't stand for anything except for your personal greed and power."

The video, which features the traditional Guy Fawkes mask-wearing spokesperson speaking directly to camera, called the operation a "call to arms" for hacktivists across the globe.

"We need you to shut down his websites, to research and expose what he doesn't want the public to know. We need to dismantle his campaign and sabotage his brand. We are encouraging every able person with a computer to participate in this operation. This is not a warning, this is a declaration of total war. Donald Trump – it is too late to expect us."

In a separate written message posted online, Anonymous listed a number of websites chosen to be the initial targets in the attack including trump.com, donaldjtrump.com and trumphotelcollection.com.

Alongside these chosen targets, the post lists a slew of unverified personal information purporting to belong to Donald Trump, including a social security number, personal phone number and the contact details of his agent and legal representation.

This is not the first time a hacking group has attempted to take on Donald Trump. In January 2016 a separate group called the New World Hackers carried out multiple DDoS attacks on his official election campaign website – effectively taking it offline for a short period of time. Recently, Anonymous leaked messages from his phone's voicemail account which included personal communications from journalists, sports stars and boxing promotors.

Anonymous, which is a loose collective of hacktivists, routinely engages high-profile targets as part of its cyber-campaigns. Previous subjects have included the Islamic State (IS), the Vatican and most recently the Turkish government.