The Queen’s “long life spent in the service of this country”, love for her family and commitment to duty will be honoured at a service of prayer and reflection following her death.

The service at St Paul’s Cathedral on Friday evening will see Dean Designate Andrew Tremlett give thanks for the Queen’s “devotion to all her people”.

Some 2,000 members of the public will be attending the 6pm service, along with the new Prime Minister Liz Truss.

In his bidding, the Dean Designate is expected to say: “We remember her long life spent in the service of this country and of her Commonwealth realms around the world.

“We give thanks for a life of devotion to God, her Creator, Redeemer and Sustainer, and of devotion to all her people.

“As we call to mind the promise made at her Coronation that all her judgements should be guided by Law, Justice and Mercy, we rejoice in her steady acceptance of this vocation.

“We celebrate her love for her family, her commitment to duty, and her calling to create unity and concord at the heart of the Commonwealth.

“We pray for the Royal Family, as they mourn their loss.

“We pray too for our most gracious Sovereign Lord, The King, that placing all his trust in God, he too may rule over us in peace with justice and compassion.”

Members of the royal family are not expected to be present at the London service, which will be broadcast live by the BBC.

Audio of the King’s televised address to the nation will be played inside the cathedral if it coincides with the service.

Liz Truss will deliver a Bible reading from Romans 14.7-12.

A spokeswoman for the cathedral said Ms Truss is expected to be joined by Lord Mayor Vincent Keaveny.

Members of the public who are attending will have visited City of London tourism office on Carter Lane earlier on Friday to collect a wristband.

All 2,000 wristbands were distributed to members of the public within three hours, a cathedral spokeswoman said.

Ahead of the service, a hundreds-strong queue has formed, winding from St Paul’s to beyond the Tube station streets away.

Attendees were dressed smartly in black suits and ties while others wore black mourning veils as they waited to take their seat inside the cathedral.

It is just over three months since the cathedral was the setting for a service of thanksgiving – attended by the royal family – during the Queen’s Platinum Jubilee celebrations.

The monarch pulled out of attending the service due to the physical demands involved.

As part of Friday’s service, Dame Sarah Mullally, Bishop of London, as Dean of the Chapels Royal, will deliver the address, and Archbishop of Canterbury Justin Welby will deliver the blessing.

Martin Ford, acting sub-organist, will play before the service, while Will Fox, acting organist and assistant director of music, will play during the service.

St Paul’s Cathedral Choir, conducted by Andrew Carwood, will sing.

Music will include Behold O God Our Defender, Bring Us, O Lord God, At Our Last Awakening, and Nunc Dimittis from Evening Service in G.

Hymns will include All My Hope On God Is Founded, O Thou Who Camest From Above, and The Lord’s My Shepherd.

The cathedral said a half-muffled single bell will toll as the start of the service, while a half-muffled peal will be sounded at the end of the service.