US President Barack Obama has cancelled his forthcoming trip to Indonesia and Australia in order to stay in Washington to oversee controversial healthcare legislation.

It is extremely rare for a president to cancel an overseas trip and it highlights the importance of healthcare reform to the Obama White House.

If the bill passes the House of Representatives, it will provide medical insurance to the approximately 32 million Americans who do not have health insurance.

The House of Representatives and the Senate have already passed two versions of the bill in November and December. The bill passed by the Senate is a slimmed down version. The House of Representatives is due to vote on this version on Sunday. Then both houses will be asked to approve a set of fixes to bring the two versions into line.

President Obama hopes by staying he will win the support of a few Democrats, who were planning to slim down the document even more. The Republicans are against the plan saying it is too expensive.

The healthcare reforms are extremely controversial and it has taken months of wrangling to thrash out a deal acceptable to US legislators. Analysts say the legislation, which will expand insurance coverage at a cost of 940 billion dollars over the coming 10 years, will cut the US deficit by 138 billion over the same period through new fees and cost-cutting measures.