28/11/2013 12:29 GMT | Updated 28/01/2014 05:59 GMT

The Public Deserve to Know Who Would Replace David Cameron Should the Unthinkable Happen

This Friday marks the second reading of my Prime Minister (Replacement) Bill. No, this does not mean we will be debating the merits of Mrs Bone replacing David Cameron as the name may suggest, but the lack of clear succession should the prime minister become temporarily or permanently incapacitated and is unable to perform his duties.

I have asked the question of what procedure is in place should the prime minister be unable to perform his duties time and time again and on each occasion ministers have failed to give a substantive response. I have been amazed at the number of different ways the ministers have dodged, ducked, and dived around the question. The responses have ranged from Harriet Harman's simply unhelpful response that "the Prime Minister is not incapacitated" to William Hague's positively clandestine explanation that "we do not consider it appropriate to talk about these plans in public".

I am not in the habit of subscribing to conspiracy theories (though I do think there was someone on the grassy knoll), but there is something quite strange about the government's refusal to state their position on the matter. Could it be that the admission that Nick Clegg is next in line to Number Ten be so scary an admission that it would be a breach of national security should this become public knowledge?

In the terrible event of an airstrike on Number Ten, we need to know instantly who would be responsible for commissioning a counter attack and more to the point we need the potential perpetrators of such an attack to know we would instantly have the capability to take such decisions. It is preposterous for us to think that there would be the need for a cabinet meeting to be called in order to decide who would be in charge. There simply would not be the time as the military would need a decision as soon as possible on what action to take. It seems to be common sense that there should be a predetermined line of succession in such an event, as is the case in the United States.

In a majority government, there would be a clear mandate for the deputy prime minister to take over in such an event, as when John Prescott was Tony Blair's deputy. The same cannot be said of Nick Clegg replacing David Cameron. Surely it is not fitting that the leader of a party that holds fewer than 10% of the seats in the House of Commons and maintains a lower approval rating than Ukip should be positioned to take over from the Prime Minister in the event of such a national emergency.

The United Kingdom has a right to know who would be at the helm in such a catastrophic event. According to MI5, the current threat level to the United Kingdom from international terrorism is 'substantial', meaning an attack is a 'strong possibility'. By default the prime minister is clearly one of the most vulnerable figures in the UK and we deserve to know the order of succession should the unthinkable happen. Be it the home secretary, foreign secretary or Chancellor, the government must be clear on who would be in charge in what would be a destabilising event. At a time when leadership would be more important than ever the last thing we would need to be doing is having a debate to decide on who's in charge. We need a clear line of succession and we need it now.

In the United States, if the president is killed, they have a list of accession of eighteen different office holders. This starts with the vice president, then the Speaker of the House, all the way down to the secretary of veterans affairs. So even if there is a mass terrorist attack on the American leadership it will always be clear who is in charge. That person will immediately take over responsibility for the nuclear deterrent and to be able, if necessary, to order retaliatory action. So, if a civilian aircraft had been deliberately crashed into the White House, killing the President and other civilian aircraft were heading towards congress it would be clear whose decision it would be as to whether those aircraft were shot down.

In the United Kingdom, if the prime minister is killed, we have no idea who would take over. Would it be the deputy prime minister, the defence secretary, the cabinet secretary, or the commander-in-chief of the armed forces? Nobody knows, and if while there is argument as to who is in control and there are civilian aircraft flying towards the Houses of Parliament and Buckingham Palace, no one would have authority to order, if necessary, their destruction.

So this is not some academic exercise but a real issue where clarity and transparency are essential. My Private Members Bill would list who would take over in the horrific event of the prime minister's death.

My order of succession is as follows:

1. The person bearing the designation of Deputy Prime Minister

2. The Secretary of State with responsibility for Home Affairs.

3. The Secretary of State with responsibility for Defence

4. The Secretary of State with responsibility for Foreign and Commonwealth Affairs

5. The Chancellor of the Exchequer

6. The Secretary of State with responsibility for Transport

7. The Secretary of State with responsibility for Health

8. The Secretary of State with responsibility for Business and Innovation

9. The Secretary of State with responsibility for Justice

10. The Secretary of State with responsibility for Communities and Local Government

11. The Secretary of State with responsibility for Education

12. The Secretary of State with responsibility for Environment, Food and Rural Affairs

13. The Secretary of State with responsibility for Work and Pensions

14. The Minister of State with responsibility for the Cabinet Office

15. The Paymaster General

16. The Secretary of State with responsibility for Culture, Media and Sport

17. The Attorney General

18. The Secretary of State with responsibility for Energy and Climate Change

19. The Secretary of State with responsibility for International Development

20. The Leader of the House of Commons

21. The Leader of the House of Lords

22. The Secretary of State with responsibility for Scotland

23. The Secretary of State with responsibility for Wales

24. The Secretary of State with responsibility for Northern Ireland

However, the person taking over would have to be of the same political party as the Prime Minister, otherwise it would pass to the next in line.

There is a real necessity for my bill. We cannot leave it for a terrorist attack and then make up our mind what happens. We need to know who will replace the prime minister.