New laws to keep terrorists behind bars for longer and reform the monitoring of suspects have been backed by MPs.

The Counter-Terrorism and Sentencing Bill is viewed by the Government as the largest overhaul of sentencing and monitoring in decades.

It includes a minimum 14-year jail term for the most dangerous terrorist offenders, who will also have to spend up to 25 years on licence after their release.

Those handed extended determinate sentences will have to serve their whole term in jail and would be denied early release.

Terrorists could also be made to take a lie detector test to prove they have reformed and are not planning another attack.

The Bill also lowers the standard of proof required to impose Terrorism Prevention and Investigation Measures (Tpims), despite Conservative-led administrations repeatedly increasing it in recent years.

The home secretary would need “reasonable grounds” for suspecting someone is, or has been, involved in terrorist activity to impose a Tpim rather than basing the decision on the “balance of probabilities”.

A Tpim notice can involve measures like an enforced curfew, tagging, living away from an address or area and restrictions on overseas travel, and are used by security services against people either involved in terrorism or present a threat but cannot be prosecuted or deported.

The Bill removes the two-year limit on Tpims, which campaigners have warned could result in courts renewing them indefinitely.

Terror attacks at Fishmongers’ Hall on November 29 2019 and in Streatham on February 2 2020 have hastened efforts for reform.

Speaking in the Commons, Justice Secretary Robert Buckland said: “We continue to face a terrorist threat in this country that is complex, that is diverse and that is rapidly changing.

“And the House has rightly noted the growing threat that we face from right wing extremists. Since 2017, we have foiled 25 terrorist plots including eight plots planned by right wing extremists.

“But we’re not complacent. We’ve already established a joint extremism unit to strengthen the partnership of work across the Ministry of Justice and the Home office and of course there is much, much more to do.”

Shadow justice secretary David Lammy said Labour supported the “important” Bill despite concerns, adding: “While it is only right that those who have committed the most heinous crimes are subjected to extended sentences, we cannot give up the hope of rehabilitation.”

Justice minister Chris Philp earlier confirmed the Government will publish its Multi Agency Public Protection Arrangements (Mappa) review before the Bill goes to the Lords, amid Labour calls for a review into strategies to deal with lone terrorists.

The Bill received an unopposed third reading and will undergo further scrutiny in the Lords at a later date.