Britain's world-leading theatre industry faces mass redundancies and venue closures because of the effect of the coronavirus lockdown, lawmakers said on Thursday. 

Parliament's Digital, Culture, Media and Sport (DCMS) committee said in a new report that more than 15,000 theatrical performances were cancelled in the first 12 weeks of shutdown from March 23.

More than £303 million ($386 million, 333 million euros) in box office revenue was lost but when additional income was factored in, losses could be £603 million.

"We are witnessing the biggest threat to our cultural landscape in a generation," the committee said.

"The failure of the government to act quickly has jeopardised the future of institutions that are part of our national life and the livelihoods of those who work for them."

The government earlier this month announced £1.57 billion in emergency funding for the creative industries, after weeks of pressure.

But while widely welcomed, there remains concern the money will not go far enough, particularly if social distancing guidelines are maintained through the popular Christmas period, which is normally a money-spinner, and into next year. 

Britain is home to nearly 1,100 theatres, more than half of which operate as charities.

The Theatres Trust, a representative body, said more than half of its members had less than three months' financial reserves, and just over a third had a cash safety net for just one month. 

Julian Bird, chief executive of UK Theatre and the Society of London Theatre, said 70 percent of theatres and production companies risked going bust before the end of the year.

Shakespeare's Globe in London has warned it faces insolvency without emergency government funding and job protection programmes. Several provincial theatres have already closed.

- 'Long-lasting impact' -

"This erosion of cultural infrastructure could have long-lasting impact on access to the arts, careers in the creative sectors and the UK's position as a world leader in this sector and as a major contributor to tourism," the committee said.

Leading figures in the arts have previously warned of mass redundancies and widespread closures, as many theatrical staff being self-employed.

The committee called for an extension to the government's furlough scheme, which is due to end in October, wider financial support, including tax breaks, and better guidance on reopening.

Social distancing guidelines could see theatres only a third full, prompting calls for the use of technology and regular testing of staff to allow the safe return of audiences.

The committee highlighted similar concerns about the shutdown's impact on live music and festivals, most of which have been cancelled due to the outbreak.

The Music Venue Trust estimated that 93 percent of grassroots music venues faced permanent closure because lack of income meant they cannot pay rents.

The National Arenas Association said the 23 UK arenas it represents will lose almost £235 million worth of ticket sales over a six-month period. 

And the Association of British Orchestras also warned UK orchestras faced up to a year of lost income because of touring cancellations and restrictions on audience numbers.