The largest health insurer in Texas wants to hike premiums for Obamacare plans by nearly 60 percent, the latest evidence that consumers may see steep cost increases this year under President Obama’s healthcare law.

Blue Cross Blue Shield of Texas has requested hikes it says could affect nearly 603,000 Texans buying health plans through healthcare.gov, the insurance marketplace set up under Obamacare. The rates have yet to be finalized and Blue Cross could choose to ramp them down, but the Obama administration lacks the authority to force the insurer to do so.