Updated

The California Assembly has approved legislation authorizing about $4.5 billion in state bond funding for a high-speed rail system backed by Gov. Jerry Brown.

Lawmakers approved SB1029 on a 51-27 vote Thursday afternoon, with Republicans opposing it.

The bill would pave the way for California to begin selling $2.6 billion in voter-approved bonds. It allocates another $1.9 billion for regional rail improvements.

If the Senate also approves the same legislation Friday, California could tap $3.2 billion in federal grants to start construction of the first segment in the Central Valley.

Democrats say a bullet train would put California on the cutting edge and bring relief to its strained transportation network. Republicans called it a boondoggle that will further hurt the state's faltering economy.