Property Tax-is it fair on properties and heritage?

With a budget looming, our finances still in trouble, income sorely needed and the challenge of keeping the component parts of the coalition happy, much has been made of the prospect of a Mansion Tax.
Taxation on the basis of ability to pay seems a well established principle in this country. Pragmatism however  is also necessary for tax raisers. The proposals for a Mansion Tax seem to bring these two principles into conflict.
Certainly it is relatively easy to collect dues from property owners. Our history is littered with examples. The Domesday Survey of 1086 was the basis for what a feudal Lord owed to the Crown. In 1662 we had a Hearth Tax and in 1696 a Window Tax which introduced the concept of tax 'bands'. Lloyd George's Finance Act of 1909 -10 introduced increased property taxation. It was therefore a radical move by Margaret Thatcher to introduce the Community Charge (Poll Tax) in 1990 based on people not property and the people didn't like it. So back to property we went with the 1993 Council Tax.
 So the first principle therefore, of an easy tax to collect, is well established even if there must be a strong case to question whether all those with wealth spend it on their property rather than gambling it or spending it on football teams, yachts, fine wine and loose women.Which of these habits makes the most sensible target?
 The second principle, of the ability to pay, is less clear cut.
 There seem to be various categories that are ill served by a new Mansion Tax. These include the elderly widow who may be reluctant to leave the family home and its memories but survives on meagre income. There is the family with lots of children which needs lots of space, is in a high value area and is funded by a huge mortgage where the net equity value is low. There is the farmer who has bought a farm for the quality of the land not the size of the house. Finally there is the large property where the owners also run a part-time business such as bed and breakfast or antiques sales. Important in this latter category are historic properties. Some of these are open to the public and attract tourists to this country or to a local area. Others, while not open, form an important part of our heritage and both have repair bills that would make the Chancellor's eyes water and they support employment in the conservation and building trades.
A Mansion Tax could use up owners' cash that would otherwise be used for repairs to our heritage. Drained of resources by public expenditure cuts, English Heritage would hardly be in a position to provide enhanced grants.Owners might well see it as more cost effective to effect cheap repairs that damage the historical integrity rather then go for listed building consent. So a Mansion Tax might be easy to collect but it might be aimed at the wrong people and it may well not be fair on properties themselves and the heritage in particular.