WASHINGTON, Sept 29 (Reuters) - Hardline Republicans in the U.S. House of Representatives on Friday rejected a bill proposed by their leader to temporarily fund the government, making it all but certain that federal agencies will partially shut down beginning on Sunday.

In a 232-198 vote, the House defeated a measure that would extend government funding by 30 days and avert a shutdown. That bill would have slashed spending and restricted immigration, Republican priorities that had little chance of passing the Democratic-controlled Senate.

The defeat left Republicans - who control the chamber by 221-212 - without a clear strategy to avert a shutdown that would close national parks, disrupt pay for up to 4 million federal workers and hobble everything from financial oversight to scientific research if funding is not extended past 12:01 a.m. ET (0401 GMT) on Sunday.

After the vote, House Speaker Kevin McCarthy said the chamber might still pass a funding extension without the conservative policies that had alienated Democrats. But he declined to say what would happen next. The chamber is expected to hold more votes on Saturday.