US President Barack Obama has made one of the most critical speeches of his presidency, as he faced Congress over his plans for healthcare reform.

Mr Obama said that failure to introduce reform had led the country to breaking point and it was now time to act.

He said he planned to improve health insurance for those who have it and to create an insurance exchange to extend cover to those who do not.

Members of Congress are preparing to fight over details of the reforms.

Mr Obama told Congress that the US was the only developed country that allowed millions of its people to endure the hardship of going without healthcare.

Everyone understands the extraordinary hardships that are placed on the uninsured, who live every day just one accident or illness away from bankruptcy, he said.

These are not primarily people on welfare. These are middle-class Americans.

But Mr Obama said the current system did not serve well those Americans who do have health insurance either.

Those who do have insurance have never had less security and stability than they do today.

More and more Americans worry that if you move, lose your job, or change your job, you'll lose your health insurance too.

He said the US spent one-and-a-half times more on health insurance than any other country but Americans were no healthier than other people.

Heckled

One Republican shouted: You lie at Barack Obama during the speech

Mr Obama set out details of his plan to reform the system.

He said that nothing in his proposal would require Americans who already have health insurance to change their coverage or doctor.

But he said he would make the insurance work better for individuals by prohibiting insurers from dropping coverage for sick patients or by capping it.

He would also require insurers to cover the cost of routine check-ups and preventative care.

For the millions of uninsured Americans, he said he would create an insurance exchange - a market place where individuals and small business will be able to shop for health insurance at competitive prices.

Mr Obama said a public insurance option could help keep the private health insurance companies honest and competitive.

But he said it would not be subsidised by the government, so would not create unfair competition for the private sector.

He added that the public option was only a means to an end, and he remained open to other ideas if they had the same effect.

HEALTHCARE IN THE US 46 million uninsured, 25 million under-insured Healthcare costs represent 16% of GDP, almost twice OECD average Reform plans would require all Americans to get insurance Some propose public insurance option to compete with private insurers Q&A: US healthcare reform Reform: Who wants what? Obama's healthcare fight-back

Mr Obama was heckled at one point when a Republican representative shouted You lie, as the president said illegal immigrants would not benefit from his proposals.

The president paused briefly and continued.

The BBC's Jonathan Beale in Washington says Mr Obama was clearly not looking for right-wing Republican support - he knows he will not get it.

Our correspondent says the speech was another strong performance from Mr Obama and an attempt to turn the tide in the healthcare debate.

But he adds the speech may have also come too late as positions are already entrenched and some of Mr Obama's supporters wonder why he did not do this months ago.

Healthcare reform has been the central issue of his change agenda but has divided both the US public and the country's political establishment.

President Obama said that Congress agreed on about 80% of the reforms that are needed.

But he said months of partisan bickering had only hardened the disdain many Americans have towards their own government.

He is facing almost unanimous opposition from Republicans, who are uneasy about the idea of government-run healthcare and who have accused Mr Obama of attempting to introduce a socialist policy.

There are, in theory, enough Democrats in Congress to approve the changes.

But in practice, the party is deeply divided between those that want a publicly-run insurance scheme and those alarmed by the borrowing necessary to fund it.