Concerns have been raised that the impact of the £2 million threshold for Labour's proposed 'Mansion Tax' will be much more widely felt than prime areas of central London alone, and would hit areas of London like Hammersmith & Fulham very hard.
Estate agents Knight Frank have conducted an analysis of where these £2 million 'threshold properties' are located in England and Wales, showing to what extent this would be true.
While Knight Frank estimate that 20% of the £2 million-plus properties are located in the London boroughs of Westminster and Kensington & Chelsea, a different picture emerges when properties valued just below the £2 million threshold are examined. It is significant because properties just below the threshold outnumber those above it.
It is notable that the local authority with the second highest proportion of properties worth £2 million after Kensington & Chelsea is not Westminster, but Hammersmith & Fulham, which is predominantly a family home market.
Tom Bill, head of London residential research at Knight Frank said "There is a misconception that prime central London is where the mansion tax would start to bite. The vast majority of properties on the £2 million threshold are located in suburban family areas of London and the Home Counties."
Local MP, Greg Hands, whose Chelsea and Fulham constituency incorporates parts of both Kensington & Chelsea and Hammersmith & Fulham, which are the two boroughs liable to be most greatly affected by the proposed Mansion Tax, has campaigned against the idea ever since it was first suggested by the LibDems and Labour. He argues that it is not even a mansion tax but a 'homes tax', as most of the properties hit will be ordinary family homes and flats.
Responding to the latest research by Knight Frank, Greg said "This research is further evidence of just how ill-conceived Labour's homes tax is. It would hit not only the very wealthy in central London, but ordinary families in my constituency and beyond.
"I and the Conservatives are opposed to this unfair, unaffordable, unworkable tax and its unintended consequences. However there is a risk that if Labour are to get in, either with a majority or supported by a LibDem or SNP coalition, they would fast track the tax to hit family homes in Chelsea and Fulham."
The analysis by Knight Frank is based on two years' worth of transaction data and relates to properties they estimate will have a value of between £1.9 million and £2.1 million in May 2015, the month of the general election.
The top 25 location of 'mansion tax' threshold properties in the UK (%) are shown below.
1 Kensington and Chelsea - 11.2%
2 Hammersmith and Fulham - 9.3%
3 Westminster - 8.9%
4 Wandsworth - 6.8%
5 Richmond upon Thames - 6.4%
6 Camden - 5.2%
7 Elmbridge - 3.8%
8 Islington - 3.8%
9 Lambeth - 3.2%
10 Barnet - 3.0%
11 Haringey - 2.6%
12 Merton - 1.8%
13 Hounslow - 1.6%
14 Ealing - 1.4%
15 South Bucks - 1.4%
16 Brent - 1.3%
17 Chiltern - 1.2%
18 Southwark - 1.2%
19 Waverley - 1.1%
20 Windsor and Maidenhead - 1.1%
21 St Albans - 0.9%
22 Guildford - 0.9%
23 Kingston upon Thames - 0.8%
24 Bromley - 0.8%
25 Sevenoaks - 0.8%