LONDON (Reuters) - A hearing in a lawsuit against BHP over Brazil's worst environmental disaster, the 2015 collapse of the Mariana dam, will begin at London's High Court on Monday, with claimants seeking up to 36 billion pounds ($47 billion) in damages.

More than 600,000 Brazilians, 46 local governments, and around 2,000 businesses are suing BHP over the collapse of the dam in southeastern Brazil, which was owned and operated by BHP and Vale's Samarco joint venture.

The collapse of the dam, which held mining waste known as tailings, unleashed a toxic wave that killed 19 people, left thousands homeless, flooded forests, and polluted the length of the Doce River - which is considered to be sacred by the Krenak indigenous tribe.

BHP, the world's biggest miner by market value, is contesting liability and says the London lawsuit, one of the largest in English legal history, duplicates legal proceedings and reparation and repair programmes in Brazil.

It says nearly $8 billion has already been paid to those affected by the disaster through the Renova Foundation, which was established in 2016.

The Brazilian government is discussing a nearly $30 billion compensation deal with BHP, Vale and Samarco, the miners said on Friday.

Pogust Goodhead, the law firm representing the claimants, said in a statement the English lawsuit is "the only way to truly hold BHP accountable".

"The English claim has pushed BHP into finally accepting they needed to do more in Brazil but this proposed deal only goes half way at best," Pogust Goodhead CEO Tom Goodhead said.

BHP said in a statement that it is "working collectively with the Brazilian authorities and others to seek solutions to finalise a fair and comprehensive compensation and rehabilitation process".

The London High Court hearing will last up to 12 weeks and will consider whether BHP is liable to the claimants under Brazilian environmental law.

It will also consider whether the Brazilian municipalities involved in the case are permitted to bring legal action and the impact of any agreements reached with BHP by claimants involved in the English lawsuit.

The suit has had a convoluted path towards trial: it was thrown out in 2020 before the Court of Appeal ruled it could proceed.

BHP and Vale also briefly fought in the English courts over their potential liability, before reaching an agreement in July to split the bill for any damages that may be awarded.