Parliament is deep in its summer recess, and domestic politics is taking second place to world events. I was glad to welcome the Prime Minister to Kemble Airfield last Thursday.

He helicoptered in and then back to London in time to chair a meeting of the Cobra committee at noon to discuss the situation in Iraq. (‘Cobra’ sounds dramatic with images of snakes and so on. It is the Whitehall bunker in which ministers and officials meet in time of national or international crisis. However, it actually stands for the much more mundane ‘Cabinet Office Briefing Room A.’) Mr Cameron came to Wiltshire to see the UK Aid Emergency Supplies Depot. It’s in a former hangar on the old RAF base and keeps at instant readiness non-food stores and equipment for emergencies, vehicles, tents, re-usable filtration containers filled with clean water, solar lights and so many other stores of an essential life-saving kind. The stores are deployed anywhere at a moment’s notice – in this case by air-drop from Hercules aircraft over Mount Sinjar. It was good to meet the people responsible and to thank them.

The UK has spent £8 million on the effort – £2m on emergency supplies, £3m for DFID’s Rapid Response Facility, £2.5m for the International Red Cross and £500,000 to help Kurdish and UN aid efforts in the region. On top of that we gave £5m to the UN and NGOs to provide food, medicine and shelter. Add to that charitable giving epitomised by my step-children, Bertie and Kitty, who cycled 3,000 miles from Toulon to Istanbul to raise funds for the Disasters Emergency Committee, and as a nation we can be proud of our generosity to the Yazidis and Christians being targeted by the evil fanatics of ISIS.

It is only right that we do what we can to help. That is why I strongly support the UK overseas aid efforts.

Yet I will not be supporting the attempts by a Lib Dem backbencher to write the UN target of 0.7 per cent of GDP on overseas aid into law. I have two reasons.

First, we should be ready to spend whatever is necessary whether that be more, or in some years less, than that figure. What would happen if at the end of a year it had not been spent? Who would pay a penalty for breaking the law in that way?

And second, these must be decisions for ministers who must weigh up the competing demands of health and education at home, defence and diplomacy overseas.