Prisons in England and Wales are nearly full, the Ministry of Justice has said, partly due to the "significant rise" in people sent to jail over last summer's riots.

Figures published yesterday show the total number of inmates was 87,668, meaning prisons are now filled to 98.1% capacity. Some 407 prisoners were put behind bars in the past week alone

The MoJ said the "usable operational capacity" is 89,399, just 1,731 above the current prison population. According to the ministry, two new prisons due to open this year should ease the strain.

But there have been no places activated under their contingency plan Operation Safeguard, when prisoners are held in cells at police stations and courts if numbers are at breaking point.

A Prison Service spokesperson said: "We have seen a significant rise in the prison population since the summer, with very strong rises following the public disorder."

Last August, Geoff Dobson, the deputy director of the Prison Reform Trust, issued a warning to the government, saying the rapid increase in prison numbers was turning some institutions into "human warehouses",

"The likelihood is that for some first time offenders that will provide a fast-track to a criminal career." he said.

But the Prison Service spokesperson insisted although managing the increase in the population is "challenging", the government is "continually developing contingencies to manage the additional population".

"We currently have enough prison places for those being remanded and sentenced to custody," he continued. "Capacity will continue to increase throughout 2012 with the opening of two new prisons from March."

"We will continue to explore contingencies arrangements should further pressure be placed on the prison estate."

On Friday December 2, 2011, the prison population reached an all-time recorded high, with numbers totalling 88,179.