THE US government heaved a sigh of relief today as its healthcare subsidy website opened as normal after earlier technical problems.

Health and Human Services Secretary Sylvia Burwell said she expected “strong and healthy growth” for 2015.

About seven million people are signed up and the Congressional Budget Office has projected a total of 13 million for 2015.

But fears remain that entrenched political opposition and legal challenges may yet collapse the programme that’s bringing healthcare to millions of previously uninsured citizens.

HealthCare.gov is an online marketplace that offers subsidies on private coverage to people who don’t have work health insurance.

The Healthcare Act contains twin “mandates” requiring companies to give full-time employees health insurance and all citizens to have health cover.

But Republicans oppose the measure and, astonishingly, the Supreme Court is due to consider its legality.