The 42-year-old former Chancellor, who is seen closing the gap with opponent Foreign Secretary Liz Truss in the race to 10 Downing Street, also vowed to weed out organisations that promote extremism in the UK and refocus the “failing” Prevent programme, a government tool intended to tackle Islamist extremism.

“There is no more important duty for a Prime Minister than keeping our country and our people safe,” said Sunak, on the campaign trail to win Conservative Party members’ votes.

“Whether redoubling our efforts to tackle Islamist extremism or rooting out those who are vocal in their hatred of our country, I will do whatever it takes to fulfil that duty. Britain is a beacon of freedom, tolerance and diversity. We must never let those who seek to undermine and destroy our way of life to succeed,” he said.

The Ready4Rishi campaign team released details of what has been dubbed as “ambitious plans” to tackle Islamist extremism and protect the UK from terrorism.

“Rishi will refocus the failing Prevent programme onto the UK’s most significant terror threat – Islamist extremism and widen the government’s definition of extremism to encompass those who vilify our country,” the statement said.

“By far and away, the single largest terror threat to the UK’s national security is Islamist extremism, but the organisation tasked with preventing terrorism in the UK is failing on this front. Islamist extremists make up roughly 80 per cent of live counter-terrorism investigations and 68 per cent of all extremists in prison, but only 22 per cent of Prevent referrals and Channel cases,” the statement noted.

“Rishi would reform the Prevent programme so that the profile of cases in the programme broadly reflects the terror threat posed to the UK.” Sunak also plans to review how the Prevent programme can be linked more effectively with mental health services to improve Prevent’s ability to differentiate between those with mental health problems and those with extreme world views.

Extremism is defined in the 2011 Prevent strategy as “vocal or active opposition to fundamental British values, including democracy, the rule of law, individual liberty and mutual respect and tolerance of different faiths and beliefs”, and “calls for the death of members of our armed forces, whether in this country or overseas”.

Sunak in his campaign pledge notes that extremists do not just want to attack our values, but our very existence.

Therefore, he intends to add “vilification of the United Kingdom” to the definition of extremism, making sure that those with an extreme hatred of the country that leads them to pose a risk to national security can be “identified and diverted away from a destructive path”.

This expanded definition is intended to help guide the public sector in its work to keep the UK safe.

The UK-born Indian-origin candidate in the race to succeed outgoing Tory leader and Prime Minister Boris Johnson also believes there have been too many examples of publicly funded charities and organisations accused of promoting extremist ideology in the UK.

“Rishi will conduct an audit of publicly funded third-party organisations – starting with those linked to the government’s anti-radicalisation work – to make sure no extremist organisation receives taxpayer money,” his campaign team said.

Additionally, Sunak’s plan to amend the Terrorism Act is intended to make the support of a proscribed organisation and the encouragement of terrorism in a prison cell an offence, even if it involves only two prisoners.

If elected Prime Minister, he intends to pass a Bill of Rights to make it easier to separate terrorists from the general prison population, making sure they can no longer abuse our human rights framework to spread their “poisonous ideology”.

Sunak and Truss are currently laying out their policy agenda on key issues as they hold hustings up and down the UK to take questions from Tory members entitled to vote in the leadership race, which closes on September 2. The results will be declared on September 5.