Jerry Petherick, managing director for G4S Custodial and Detention Services, said: "The mobilisation of any prison is a complex and challenging operation but the size and scale of Oakwood - the largest prison in the country - made this even more acute.
"As well as the logistical hurdles in new establishments, prisoners test the regime as well as the members of staff, who may be new to prison life.
"We have already taken steps to make improvements, appointing a dedicated task-force to address problem areas, such as the prevalence of drugs, while providing additional funding where necessary. This is starting to yield results."
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Dry for much of the day with possible brighter spells in the east. Outbreaks of rain will spread southwards later in the day.
Another rather cloudy and mild day. Although dry for most the odd spot of drizzle is possible, mainly over high ground.
D-Day veterans from the West Midlands were given France's highest honour today, 18 months after a pledge to award every living soldier.