British fashion officials are warning about the perils of a “no-deal” Brexit as London Fashion Week begins.

At an opening event Friday morning, Stephanie Phair, chairwoman of the British Fashion Council, said the industry is urging Britain’s government to find a Brexit deal rather than leave the European Union without new arrangements in place.

She said studies show a “no-deal” Brexit would cost the fashion industry well over 800 million pounds ($1 billion) and urged the government to negotiate a deal that would ensure “the healthy and steady growth of the fashion industry.”

She spoke at the start of a five-day fashion fest that will feature big names like Burberry, Christopher Kane and Victoria Beckham.

One of the main events is a Fashion for Relief fashion show organized by model Naomi Campbell.

Many of the shows are also expected to showcase up-and-coming designers as London builds on its reputation for innovative street fashions.

As the event started Friday, Extinction Rebellion climate protesters glued themselves to an entrance to the extravaganza.

The group said five of its activists covered themselves in fake blood and staged a “die-in” to protest fashion’s contribution to the “climate and ecological crisis.” The group says it plans actions throughout the event.

London Fashion Week officials declined to comment on the protest.