A charity for ex-prisoners is warning that overcrowding could lead to unrest in our prisons this summer.

Mark Leech, the chief executive of Un-lock says there are too many people in jail..

Click here to watch Graham Satchell's interview with Mark Leech

I served 14 years in prison for robbery and came out in 1994 have been in 62 of Britain's prisons.

Mark Leech

My prison career particularly in the early days was characterised by riots rooftop protests assaults on staff.

I was a very violent and angry young man basically.

Certainly overcrowding played a large part in that - because you could be locked up for 23 hours out of 24 and often 24 If the weather was inclement or they didn't have the staff to man the exercise yard.

In that kind of atmosphere its inevitable unrest will occur.

Basically it means you will spend more time in your cell and the regime in terms of education workshops visits will be curtailed.

Prison staff have to cope with those high numbers - tensions fray and it can lead to unrest and it can lead to riots.

We should care for a number of reasons.

Of the 71 thousand people inside our prisons, all but 24 are coming back out - and they are going to live next door to people like you and me and everyone else who's watching this programme.

My fear is that if we have a long hot summer and we have these levels inside our prisons it can so easily become unmanageable.

The combination of overcrowding and a long hot summer can lead to unrest and that's the last thing we need or the country needs or prison service needs right now.

Click here to watch our interview with David Roddan

On Breakfast we interviewed David Roddan, General-Secretary of the Prisoner Governors' Association. He said:

"We can't cope with a system that is clogged up with short term offenders."

We are concerned about overcrowding, but our prison system is very different now to what we had in 1990...we do have 13,000 prisoners sharing cells which are designed for one...we can't cope with a system that is clogged up with short term offenders. Prisons should only be for violent and serious offenders...At the moment we are using early release on tags for short term offenders, the failure rate is very low, only 4%...I think we could clear our prisons of 3-4,000 prisoners on very short sentences.