You were head of the Navy. What qualifications do you have for advising the Government on counter-terrorism?
COLIN FORSYTH, Plymouth
I served for six years in the intelligence world as head of naval intelligence and later chief of defence intelligence. I was closely involved with counter- terrorism and I'm at home with the UK intelligence agencies as well as having good links with foreign intelligence and security agencies. That said, I do not have a magic wand and am only too aware of the difficult task ahead.
How worried should I be when I take the Tube to work each day?
ADRIAN PORTER, London SW8
I often use the Tube and love my Oyster card. The general threat warning in the UK is severe and it behoves us all to be vigilant whenever we are in crowded places. The threat we face is real and passenger safety is a priority. That said, the chances of any individual being killed or injured in a terrorist attack on the Tube are very, very small. The Government is working to make sure everything that can be done to protect passengers is being done. I've been tasked by the Prime Minister to look at further measures to ensure protection for transport and crowded places.
Have you always been a Labour Party supporter?
BEN YORKE, Ashford
I've served for 41 years in the Royal Navy and, during that period, was completely non-partisan or political. This is true of all regular officers and a great strength of the British system. Now as a peer, in common with those who have been sectioned under the mental health Act and criminals, I am unable to vote in a general election.
Senior military officers are renowned for their blunt talking. Is it difficult being a politician suddenly?
FIONA DARKELL, Manchester
I have often got in trouble for my blunt talking and can't see that changing. Watch this space.
Do you accept that the liquids ban on planes is mere window-dressing and a huge inconvenience to passengers?
BRIAN CONNOR, Brussels
No. It related to a specific threat and we can all be thankful to the vigilance and competence of our agencies, security forces and police that those using aircraft are now safer. We believe that the alleged plot of 10 August 2006 involved a credible method, using liquids and similar substances, of constructing a device capable of bringing down an aircraft - the Government therefore had to put robust measures in place.
British troops left Northern Ireland this week after 38 years. When do you think they will leave Iraq?
PETER McPHERSON, Norwich
As soon as the Iraqis are able to look after their own internal security and ask us to go.
How will we know when we have won the 'war on terror'?
MIKE COOPER, Rochester
I do not like the term "war on terror". The term "war" can be divisive, playing right into terrorists' hands. Terrorists are criminals and murderers. What is important is tackling violent extremism. This is something that will take time.
Is al-Qa'ida behind most of the plots we hear about?
NEIL MORRISON, Manchester
Some of the plots in the UK have been directed by al-Qa'ida, some more loosely influenced by it.
You once lost some classified documents while walking your dog. Are you really a fit person to oversee British security?
TANYA HARRIS, London
One of the good things about Britain is we do not re-penalise people for stupid mistakes. I was court-martialled, punished and learnt a lesson. Since then I've served in the intelligence world and am more aware than most of the need for care over classified material.
The terrorism in London has targeted buses and Tube trains. Yet we don't have airport-type security on these forms of transport. Please explain.
CAROLINE SUTCLIFFE, London W4
Millions of people travel by Tube and bus every day and it would be impractical to implement airport-style checks. However, there are measures in place to enhance security.
Internment was a disaster in Northern Ireland. Why reintroduce it?
BEN OLIVER, Edinburgh
Presumably, you are referring to pre-charge detention that can run to 28 days. It is not the same as internment because there are important safeguards built in. First, there's an upper limit after which the person needs to be charged or released. Second, all detention more than 48 hours must be approved by a judge. Liberty of individuals is important but has to be balanced against expectations of our citizens that the Government will ensure their right to life.
Did you support the war in Iraq? And if you did, knowing what we now know would you still support an invasion?
K AHMAD, Hackney
I was a member of the chief of staff's committee during the lead up and invasion of Iraq. Hindsight is a wonderful thing but one thing is for sure, I am certainly glad Saddam Hussein is no longer in power.
Do you think our involvement in Iraq puts Britain at greater risk from terrorism than it does other countries in Europe?
ANTHONY FIELD, London N19
There are a number of complex factors that put us at greater risk than most countries in Europe. It's not as simple as just being about Iraq.
Now that security is making life a misery for air passengers, isn't it time airport shopping malls are cleared away to create more space for check-in?
TONY FROST, Southend
Some have removed retail units to accommodate check-in but in some others it is not possible without seeking planning permission and undertaking major works. .
You recently talked about people 'snitching' on suspicious-looking neighbours. Is there any evidence that citizens are following your advice?
JEREMY THOMAS, Oxford
Perhaps "snitching" wasn't the right word. What I meant was that it's important we're all vigilant.
Do we really need two new aircraft carriers?
BEN WHITE, London SE8
We will be safer once they are in service and I predict at some stage in the next 50 years the nation will be grateful for them.
You commanded a frigate sunk in the Falklands War. How did that affect you?
IAN BURTON, Nottingham
It made me less arrogant, taught me how to handle adversity, made me realise the importance of people and to understand the horror of war as well as the necessity to be trained and capable to succeed in that most intense and demanding environment.
Why are so many people arrested for terrorist offences, and yet so few charged? Isn't this just more bungled intelligence that further alienates British Muslims?
MARTYN STEWART, Brighton
Our intelligence and police services are among the best in the world but we must do better at explaining what we are doing and why. About a third of those arrested under terrorism legislation or as part of a terrorist investigation have been charged with either a terrorist offence or another criminal offence. This year alone, a series of trials have resulted in 31 individuals being found guilty and sentenced to periods of imprisonment of up to 40 years.
Who are your heroes?
REBECCA DUNCAN, Harpenden
Nelson, Admiral Walter Cowan, Churchill, Nelson Mandela, Field Marshal Slim and HM the Queen.
Do you like the Village People song 'In the Navy'?
HENRY O'BRIEN by email
I prefer Rod Stewart's "Sailing", admire Abba and have a soft spot for Kylie Minogue.Reuse content