Business Secretary Vince Cable has signalled his continuing support for a new tax on high-value properties.
Mr Cable told Liberal Democrat activists that making the tax system more progressive - with a heavier burden falling on the better off - was "absolutely integral" to Government's economic reforms.
With high earners able in large measure to escape taxation by moving their wealth around the world, he said that targeting "property and land" was one way of ensuring they were made to pay.
In opposition Mr Cable had proposed a so-called "mansion tax" levied annually on properties worth more than £1 million - later raised to £2 million - but the policy quickly unravelled.
However addressing the Social Liberal Forum in London, Mr Cable made clear that he had not abandoned the idea of some form of new tax on property.
"As a party we have got to think through how you introduce a more progressive tax system in an environment where capital and, to some extent, people are mobile - certainly high earners," he said.
"I think this inevitably draws us back to property and land. We are going to have to address the issue of wealth, property, land as part of a fundamental progressive reform of the tax system.
"I see that as absolutely integral to delivering the combination of measures that we are really going to need to restructure the economy. We mustn't lose sight of that."
The Treasury, however, has already ruled out a mansion tax and any alternative proposals for a property tax are likely to run into fierce opposition from Tories within the coalition.