I don't understand the argument that it is somehow more worthy to give your money to the Government via inheritance tax rather than to provide financial stability for your family or to assist charities that directly help people. The noble thought that it would be wisely spent by our fabulously competent governments (of any party) to make life fairer for the less fortunate in society is risible and a triumph of hope over experience.
The National Audit Office calculated that the Coalition government wasted £31 billion in the first 18 months of government alone.
Under various governments £26 billion has been wasted on computer blunders, £18 billion on ID cards. Not to mention taxpayers subsidise MPs' catering costs by £6 million each year. You'd think on a salary of over £67,000 they could afford their own cheese sandwiches.
It's very easy to spend money that isn't yours and Governments find it easier than pretty much anyone else.
They already have income tax, national insurance, tax on savings, tax on spending, capital gains tax, corporation tax, stamp duty etc etc. What do they want - blood?
The roughly £3 billion a year that inheritance tax raises is far better spent ensuring financial stability for your family or would mean a hell of a lot to charities that help people directly on the ground. Whereas the way that Governments chuck money away they could waste that £3 billion in a couple of months if they continue to squander it at the rate they wasted it in the first 18 months of power. The same would be true of a Labour government.
In general money is best spent at the closest level to the recipients - cut out the middle man i.e. the Government.
OP if you think it is too difficult to talk to your parents on the basis that they might think you are fishing for an inheritance ask them whether they would sooner the Government got their legacy or their favourite charities.
I would be delighted if my adult children had approached me if I had not already thought about it. But as you can probably guess I've already made arrangements and sorted out powers of attorney. 