Atkins has evacuated 170 staff from the Kingdom and is flying them to other offices in the Middle East.

An Atkins spokesperson said: “We have activated our contingency plan for Bahrain and are now decanting our people to other Atkins locations in the region to ensure the safety of our people and continued service to our clients.”

The firm will continue to work on projects in Bahrain from regional offices.

Scott Wilson and Hyder have also closed their Bahrain offices and other UK consultants and contractors are expected to follow suit.

The Foreign Office said it would charter planes to help people leave Bahrain.

It advised any British nationals without a “pressing reason” to stay to leave via Bahrain International Airport today on commercial flights.