Leaders from major church denominations have signed an open letter pleading with Treasurer Scott Morrison to stop Australia's foreign aid from falling to the least generous level in history.

One of the signatories, Australian Christian Churches president Pastor Wayne Alcorn, heads the denomination of the Shirelive church that Mr Morrison attends in Sydney's Sutherland Shire.

Churches have urged Treasurer Scott Morrison to reverse cuts to foreign aid. Credit:Andrew Meares

The Coalition government has stripped $11 billion from the aid budget since coming to office and another $224 million is scheduled to be cut next financial year.

"We believe it is time to reverse course," the letter said. "These cuts damage and undermine programs which have a direct impact on the lives, livelihoods, security and opportunity of many of our region's poorest and most vulnerable people."