Carrie Symonds, the fiancee of British Prime Minister Boris Johnson, is taking extra precautions against the coronavirus pandemic amid her pregnancy.

According to The Sun, Carrie Symonds cancelled the celebrations of her 32nd birthday on Tuesday, in the wake of the novel coronavirus that causes COVID-19, and has been in self-quarantine in the grace-and-favour flat above No.11 Downing Street.

The public relation professional has been avoiding visitors at her flat, which is just above Boris Johnson's coronavirus "war rooms" in Westminster. The No10 flat, the official headquarters of the Government of Britain and residence of the PM, has been filled with Johnson's trusted staff who have been working round the clock on ways to stop the virus's spread.

The outlet reports that the army of aides and junior staff are spending their night on mattresses or sofas in their offices, ordering takeaway orders of pizza and Nandos chicken. An insider at the said 'war room' described Britain's coronavirus battles as a "race against time."

"The health horror is still ahead of us, but the economic horror was now. I can't imagine what it would have been like if the No10 and No11 teams were not anchored together in last week's scenario," the source said.

Symonds is spending most of her time at the house, only stepping out to walk her dog Dylan in nearby St James's Park. However, the 32-year-old spent the weekend at Chequers Court, the country house of the Prime Minister, to spend some quality time with her partner.

The soon-to-be mother uses FaceTime to keep in touch with her mother, aged over 70, as advised in the guidelines issued by the British Government for the public.

Boris Johnson and Carrie Symonds
The British leader, who took office last summer and then swept to an emphatic victory in the country's December general election, will be the first UK prime minister to wed while in office for 250 years. Photo: AFP / Oli SCARFF

Meanwhile, Johnson has made several changes to his daily routine in the wake of the virus which has caused over 200 deaths in the UK. The 55-year-old has sacrificed some of his home comforts and has switched to a vegan diet to ditching his beloved chorizo, cheese, and red wine.