In a Westminster Hall debate, MPs from the Black Country and Staffordshire pressed waterways minister Rebecca Pow over the future of a funding deal for the the Canal and River Trust.
They have called for clarity over the continuation of the trust's 15-year grant with the Department for Environment Food and Rural Affairs (Defra).
The agreement was signed in 2012. It was expected to be extended in July following a scheduled review but has been hit by delays sparked by Covid and changes in government.
Lichfield MP Michael Fabricant, who called for and opened the debate, said the funding would help safeguard the future of Britain's 2,000 miles of canals and rivers.
He told MPs: "The minister needs to confirm the timeline for this vital decision so that the trust is able to plan for the longer-term, to plan the vital investment in our waterways, and to give reassurance to all the millions who care so passionately for them, that that the Government remains committed to the future of our nation’s canal network.
"For, let us be clear, under-funding our canals would be a false economy. Once they begin to decline, their demise may become inevitable and their benefits lost, as they enter a vicious circle where they fall into ever worse neglect and disrepair."
Also taking part in the debate were Aldridge-Brownhills MP Wendy Morton, who pointed out that canals bring in £4.6bn in benefits, and Stone MP Sir Bill Cash, who called canals "the lifeblood of the economy".
Ms Pow confirmed that the review into the funding – which stands at £52.6m until 2027 and is one quarter of the trust's annual income – was still ongoing.
However, she refused to give a date for any announcement and said it had always been the intention to reduce the trust's dependency on the grant.
Ms Pow told MPs the review was "scrutinising the trust's performance" to see whether the grant had been value for money, and was looking closely at "the case for continued funding".
"It is progressing now and with speed," she said. "I am unable to comment in detail further on the outcomes, but it will be announced forthwith – not shortly, forthwith."
She added: "The announcement will be made as soon as possible."
Ms Pow said a property endowment of £400m – included as part of the 2012 deal – was now worth £1.1bn.