Elizabeth II memorial could cost up to £46m

Elizabeth II was the country's longest-reigning monarch

A national memorial to Queen Elizabeth II could cost as much as £46m, with the government calling on leading artists, architects and engineers to put forward ideas for the monument.

The permanent memorial to the country's longest-reigning monarch will be placed in St James's Park, close to Buckingham Palace in central London.

The government has set a provisional construction budget of between £23m and £46m excluding VAT for the project, with the money for it coming from public funds.

The project aims to create "an emotionally powerful place", which includes "celebratory spaces", areas to encourage reflection and a standalone monument, organisers said.

The permanent memorial will be placed in St James's Park

The memorial will be located in the area of the Grade I-listed park adjacent to The Mall at Marlborough Gate.

It will include the land surrounding the pathway down to the lake and the Blue Bridge crossing, as well as across the other side to Birdcage Walk.

One artist will be tasked with depicting a likeness and figurative representation of the late queen, to be located near the Marlborough Gate entrance.

It is understood the project's budget is a guide figure to enable interested design teams to develop comparable proposals and not a final figure, which would be dependent on the nature of the winning design.

The provisional cost also includes a replacement of the Blue Bridge in St James's Park.

Campaign group Republic has criticised the decision to use public funds, calling it "an appalling waste of money when so many are living in poverty".

'Reflection as well as celebration'

The Queen Elizabeth Memorial Committee, which will select the winner, said it would judge all submissions against a value for money criteria.

The late queen's former private secretary Lord Janvrin, chairman of the committee, said: "The memorial must be - simply - a beautiful place, somewhere to visit with family and friends, to enjoy and to reflect on an extraordinary life."

"We are looking for teams who thoroughly understand and connect with our ambitions for the project," he added.

Pat McFadden, chancellor of the Duchy of Lancaster, said: "This national memorial will provide a permanent tribute to the late queen's legacy, offering space for reflection as well as celebration."

The two-stage competition has opened, with the winners to be announced in the summer.