How Many MPs' Children Are In The Armed Forces?

I see that the youngest son of Senator John McCain is joining the US Marines:

According to Time.com:

This September, Senator John McCain's youngest son, Jimmy, 18, will report to a U.S. Marine Corps depot near Camp Pendleton in San Diego. After three months of boot camp and a month of specialized training, he will be ready to deploy. Depending on the unit he joins, he could be in Iraq as early as this time next year, and his chances of seeing combat at some point are high....

..... McCain's personal influences on Jimmy appear to have outweighed the privileges that came with being his son. McCain is rock-star famous, and his wife Cindy came to the marriage with money as the daughter of a Budweiser distributor. While others have signed up for duty — the sons of both Senator Kit Bond of Missouri and Tim Johnson of South Dakota have served combat missions in Iraq — it is nonetheless unusual for children of that background to enlist. By comparison, a recent study by Public Citizen's Congress Watch found at least 32 examples of congressional family members who were lobbyists.

I wish Jimmy McCain all the luck in the world out there. Inevitably ,as a side effect this will change the US electorate's view of his father if he puts himself forward again as a presidential candidate.

But it got me thinking - we've had some distinguished ex-military people in the House of Commons - not least being Paddy Ashdown. But does anybody know how many children of MPs are serving in our armed forces at the moment?

Hat Tip : Andrew Sullivan (again)