Extinction Rebellion (XR) has written to senior executives at UK-based insurance firms urging them to end their coverage of fossil fuels.

The environmental campaign group sent the letter on Monday as it prepares to stage a week of protests both in London and across the UK from October 28.

The letter told insurance bosses to “make a pledge to get out of new oil, coal and gas – or face actions and protests”.

XR said members of the public will join its activists to target insurers through nonviolent actions in the City of London.

After three days of intensive action in the capital, the campaign will spread out to target the offices of insurers in towns and cities across the UK.

The letter said: “You have 14 days from today to make a public declaration that you will stop insuring all new fossil fuel projects.

“Your failure to make such a declaration by October 28 will mean that your business in the UK will become the focus of a wide range of nonviolent direct actions by thousands of XR activists and their allies during a week of actions in London and across the UK, and in the weeks and months after that.”

It comes after XR staged similar protests targeting City of London insurance firms in February as part of a global action week which saw dozens of actions held in 27 cities across the world to highlight the role of the insurance industry in the climate crisis.

Many insurance firms earn profits by underwriting fossil fuel projects such as oil rigs and coal mines.

But the industry also faces significant challenges from global warming as increasingly severe impacts increase the risk of liability for certain types of insurance and drive up costs.

Steve Tooze, the campaign spokesperson, said the insurance industry “are choosing to bet on profits from underwriting oil, gas and coal projects that are accelerating the climate crisis to levels that could destroy our civilisation in our lifetimes”.

“Then they are charging us more and more to insure our homes against the increasing risk of flooding.

“The campaign’s actions from October 28 onwards will be designed to show what the insurance industry’s heartless strategy means to billions of people, including people in the UK: flooding, food shortages and social unrest and collapse.”