During the coalition negotiations, the Tories agreed to introduce the Lib Dems' plan to raise the income tax threshold to £10,000. As part of paying for this, they agreed to increase Capital Gains Tax to 40 percent. But, crucially, this increase only applies to non-business assets.
What makes this so important is that there is no legal or HMRC definition of a non-business asset. All the definitions are of what business assets are, not what non business assets are.
Tory MPs don’t like this hike in Capital Gains because they don’t like raising taxes, they think that the increase will make Britain uncompetitive compared to European countries and because a lot of them are receiving a huge amount of correspondence from constituents complaining that this wasn’t in the Tory manifesto and wasn’t what they voted for. But I suspect that the absence of a definition of a non business asset provides enough wiggle room for something to be worked out that will assuage the concerns of the vast majority of Tory MPs.