Thames Water has won its court appeal over a restructuring plan that will give it a £3 billion loan to keep operating.
The Court of Appeal ruled in favour of the loan that allows the embattled and highly indebted water company time to raise more private investment.
An appeal by environmental campaigners, including Lib Dem MP Charlie Maynard, and a group of creditors was dismissed by judges after a hearing last week.
Opponents to the loan argued that the high costs of the emergency loan, which has an interest rate of 9.75%, was not in the public interest.
Thames Water has debts of £19 billion and the creditors argued that a special administration would be a better way of allowing the company to sort itself out, after it was unable to secure more investment from existing shareholders due to sizeable fines from regulator Ofwat.
Thames Water chief executive Chris Weston said in a statement:
"We remain focused on putting Thames Water onto a more stable financial foundation as we seek a long-term solution to our financial resilience. Today's news demonstrates further progress."
He said Thames continues to work with its creditors, "enabling us to access liquidity to continue to implement our turnaround plan so we can deliver better results for our customers and the environment".
Thames said it is assessing proposals it has received from businesses wanting to invest.
Matthew Topham, lead campaigner for We Own It, a group campaigning for utilities to be brought back into public ownership, said: "As a vital public utility serving a quarter of the population, the environment secretary should be charting a course to safer waters by putting Thames into special administration and public ownership.
"Instead, Steve Reed has just flushed nearly £1 billion of households' cash down the drain in the form of interest payments and professional fees by supporting this terrible deal to go ahead."