Hartlepool MP Jonathan Brash stressed the importance of the scheme and lobbied ministers over the issue in the House of Commons in March, external.
He said while the defences had been maintained over the years, their age meant they could fail, putting “communities at severe risk”.
In a letter to Secretary of State for Environment Steve Reed, he said: “Without dedicated funding for the repair and future-proofing of the Greatham Creek flood defences, we risk undermining broader flood mitigation efforts in the area.”
The government said it was investing £2.65bn over two years to improve flood resilience.
A decision is expected to be made on the proposals by Hartlepool Borough Council in November.