Meghan Markle's police bill rockets as she flies back to UK without baby Archie

The couple's last official royal engagement is expected to be on March 9 - before they step back as senior members of the family. (Image: PA)

Meghan Markle's decision to fly back to the UK without baby Archie is causing a £50,000 headache for her police bodyguards, according to reports.

The Duchess of Sussex is expected to return to Britain this week for the first time since Megxit rocked the royal family.

While taxpayer-funded bodyguards will have to protect her in London, others will need to stay in Canada to guard little Archie.

Harry arrived ahead of his wife last week. They are both expected to attend a Commonwealth Day service with the Queen at Westminster Abbey on March 9 - their final royal engagement.

But the couple's jet-setting lifestyle is reportedly causing a "real headache" for the Metropolitan Police, whose officers serve as Meghan, Harry and Archie's minders.

The force pays for the officers' salaries, overtime, overseas allowance, pensions, flights and accommodation - all of which spiral in cost whenever Meghan and Harry travel abroad.

A royal insider told The Sun: "Meghan’s London jaunt is proving a real headache.

"Next week will demonstrate the colossal challenges and sums involved when Harry and Meghan are in London needing security just as much as Archie. It’s as much as another £50,000 to what’s already being run up."

Meghan and Harry are stepping back as senior royals and will split their time between the UK and North America, as well as vowing to become "financially independent".

But there has been no official announcement about who will foot their policing bill after Megxit.

Recently, the Canadian federal government confirmed it would no longer provide security for the couple when they cross the Atlantic - as they won't be working royals any more.

This presumably places responsibility for the bill squarely with British taxpayers.

Meanwhile, Meghan is reportedly set to make her debut at the Met Gala in New York in May after stepping down from royal duties.

The former actress has been invited to attend the star-studded soirée along with Vogue's editor Edward Enninful on May 4.

But it appeared that she will be going without Prince Harry , a source told Sun Online.

This year's Met Gala theme will be based 'Orlando', a novel written by Virginia Woolf that sees the main character change sex.

The Duchess is therefore expected to adopt a 'glamorous androgynous' look at the event.