LONDON • Mr Boris Johnson entered Downing Street as British Prime Minister for the first time yesterday amid speculation over whether his far younger girlfriend, Ms Carrie Symonds, will accompany him.

The twice-married Mr Johnson, 55 - declared the Conservative Party's new leader on Tuesday and confirmed as premier by Queen Elizabeth II - is dating the party's 31-year-old former director of communications.

Ms Symonds, an avid environmental campaigner, had worked on his re-election campaign as London mayor in 2012. The two have been a public, but largely discreet, couple since the serial philanderer split last year from his wife of 26 years.

In the run-up to Mr Johnson's takeover, British newspapers have been rife with rumours over Ms Symonds' future role as the nation's "first girlfriend" and whether she will also live at his 10 Downing Street headquarters. He refused to discuss the matter on several occasions during the campaign.

It is believed the couple were living together in south London after Mr Johnson and his estranged wife Marina Wheeler, 55, confirmed their separation last September.

Ms Symonds was thrown into the spotlight in June when her neighbours called the police after they overheard her screaming at Mr Johnson during a late-night row. The couple have reportedly moved out of the residence since.

Ms Symonds is the daughter of Mr Matthew Symonds, a co-founder of The Independent newspaper, and Ms Josephine McAfee, a former lawyer there with whom he had an extra-marital affair.

Ms Symonds grew up in southwest London, attending the exclusive Godolphin and Latymer School before taking theatre studies and art history Warwick University in central England.

She began working for the Conservative Party in 2010 as a marketing director for MP Zac Goldsmith, and came into contact with Mr Johnson when working on his mayoral campaign. She went on to hold various press jobs at party headquarters, including director of communications, but left that role last year.

An avid campaigner against plastics, she has since joined the global marketing team at conservation charity Oceana.

The new Prime Minister's aides are said to be divided on how to handle the relationship - and whether Mr Johnson should pose for photos with Ms Symonds when he first enters Downing Street.

Some fear presenting them as a couple could cause protocol problems and draw undue attention to his history as a serial cheater.

Mr Johnson has four children with Ms Wheeler - his eldest daughter is just five years younger than Ms Symonds - as well as a daughter from a 2009 fling.

During a court battle relating to that birth, it was alleged he had had another child out of wedlock, but that remains unclear and Mr Johnson has refused to comment.

He and Ms Symonds are reportedly set to wed next year once he has divorced, with some advisers reportedly advocating that she keep a low profile until then.

If the pair were to marry, Mr Johnson would become the first British prime minister to wed while in office in 250 years.

AGENCE FRANCE-PRESSE