Offenders who ve served 40% of their prison terms will be eligible for early release. It s necessary, says the government, because of severe overcrowding in jails. There are fewer than 500 spaces left in men s prisons in england and wales, a crisis made worse by the convictions of hundreds of people involved in riots last month. Our senior uk correspondent sima kotecha was given full and rare access to hmp pentonville in london and this is what she found. Siren blares. Chaos in hmp pentonville. Shouting. We re the only broadcast journalists given access. . . It s a code red. . . To one of britain s most dangerous jails since the current crisis. 0k, come on, folks. And some prison officers are so frightened of being targeted on the outside that we ve had to blur theirfaces. Hmp pentonville! staff are overstretched. . . Another alarm here. . . And on the verge of breaking point. You worry about, you know, opening the door in the morning and making sure that they re alive. Anything could