A man was sentenced to a whole life term Wednesday for the murder of veteran British lawmaker David Amess after stabbing him to death in an attack in a church where he was meeting voters.

Ali Harbi Ali, 26, a British citizen and son of a former media adviser to a prime minister of Somalia, repeatedly stabbed Amess in an attack last October for what he said was revenge for the lawmaker's support for airstrikes on Syria. Ali, who was on Monday found guilty of murder and preparation of terrorism after the jury took less than half an hour to reach a verdict, was jailed for life, meaning he will never be considered for release.

"It's clear that the man who begins a life sentence today is a cold, calculated and dangerous individual," Metropolitan Police Assistant Commissioner Matt Jukes said in a statement outside court following the sentencing.

"David's murder was an attack on democracy and we will never let terrorists prevail."

The killing of 69-year-old Amess, a married father of five children and a member of Prime Minister Boris Johnson's Conservative Party, sent shock waves through Westminster and led to calls for better security for members of Parliament, coming just five years after another lawmaker was murdered.

In a statement read out by Jukes outside court, Amess's family said they felt no elation at the sentencing. "Our amazing husband and father has been taken from us in an appalling and violent manner. Nothing will ever compensate for that," they said.

"We will struggle through each day for the rest of our lives. Our last thought before sleep will be of David. We will forever shed tears for the man we have lost. We shall never get over this tragedy."

Ali told detectives he had spent years planning to kill a lawmaker and had previously carried out reconnaissance at the Houses of Parliament, and of two other parliamentarians, including Cabinet Minister Michael Gove.