The current system is criticised for being unfair
Improving the care available for the elderly will be Labour's domestic policy "priority" should it win the next election, Gordon Brown has said.
As he prepares to unveil a series of care proposals in the Queen's Speech, he told the Daily Mail the current system was not "fit for purpose".
Labour will propose free care at home for 280,000 of the frailest people and help for others to stay in their homes.
But the Conservatives described the as "confused and short on detail".
They said they did not address the needs of the thousands of people already in residential homes and those likely to enter them in the future.
Many pensioners have been forced to use up their entire savings and, in some cases, sell their homes to pay for care.
In an article for the Daily Mail, Mr Brown said how a country looked after its elderly was a "hallmark of a civilized society".
A rapidly ageing population and higher expectations of care meant policymakers were now facing a bigger challenge that ever before.
"We will begin to set out our bold plans for reform because our current system is simply not fit for purpose," he wrote.
"It is not right that people already struggling with the loss of independence, who have worked hard all their lives, saved for their retirement, are being forced to run down their savings or sell their homes to fund their care."
In his conference speech in September, Mr Brown announced plans for a new service across England providing free care for the most needy.
Mr Brown said proposals in the Queen's Speech - which traditionally outlines the government's legislative programme for the year ahead - would "protect those with the greatest needs" from having to pay for their care while enabling them to stay in their own homes.
The government will also pledge to provide six weeks of at home personal support for about 130,000 people who have not previously received assistance, Mr Brown added.
"This is just a first step," Mr Brown adds.
"In the New Year we will publish detailed plans for a new National Care Service and I am clear that this will be the first domestic priority of a new Labour government."
The BBC's Political Editor Nick Robinson said the ability to cope in old age was an issue worrying millions of people and was now viewed by all parties as a problem that could no longer be put off.
But he said the cost of providing free personal care beyond a limited group would be
The Conservatives said the government had already downgraded the number of people who will receive free care under its plans from the 350,000 figure first envisaged.
It said ministers were planning to pay for their national care pledge by scrapping disability benefits for more than 2.5 million pensioners while doing nothing for those already in care homes or and the thousands who entered them each year.
"While we want to help people stay in their homes for as long as possible, Labour's policies are confused and short on detail," said shadow health secretary Andrew Lansley.
"Labour's plans are all about political point-scoring, not the long-term care of older people."
The Conservatives have put forward proposals of their own in which anyone paying a voluntary fee of £8,000 upon retirement would get all their residential care costs paid for by the state, a policy which Labour says does not added up.
Support for the elderly is one a range of measures set to be included in the Queen's Speech, with proposals on banking reform, school report cards and flood protection planning also set to feature prominently.
Opposition parties have cast doubt on how many bills can be passed given that a general election must be held by 3 June at the latest and Parliament will only be sitting for about 80 days before then.
The Liberal Democrats have called for the Queen's Speech to be cancelled and for ministers to focus on a package of reforms to Parliament instead.