A consultation document published by the DCLG this afternoon says that councils would be placed in special measures if 30 per cent or fewer major applications have been determined within 13 weeks over a two-year period.
A second measure set out in the consultation document would see authorities placed in special measures if their proportion of major decisions overturned on appeal is greater than 20 per cent over two years.
The two measures were hinted at in an impact assessment on the Bill published last week.
An analysis by Planning of official data on councils’ performance on deciding applications on time between March 2010 and March 2012 revealed that six local authorities - Haringey, the London Borough of Kensington and Chelsea, Torbay, the London boroughs of Hounslow and Barking and Dagenham, and Cambridge – performed under the 30 per cent threshold.
But the impact assessment said that currently no major applications would qualify for submission to PINS based on authorities having a poor appeals record as no council has more than 20 per cent of its major decisions overturned at appeal.
The consultation document said: "We intend to set these thresholds so that only very poor performance would result in an authority being designated: where 30 per cent or fewer major applications have been determined within the statutory period or more than 20 per cent of major decisions have been overturned at appeal.
"We consider it important that a designation could be made on the basis of either measure (rather than a combination of the two), so that applicants can access a better service where speed or quality is a significant issue."
The consultation document proposes that the threshold for designation on the basis of processing speeds should be raised over time "to ensure that there is a strong but achievable incentive for further improvement in performance".
It proposes that any designation would last for at least a year, but would be subject to review "well before that year ends, so that the authority has every opportunity for the designation to be lifted at the end of the one-year period".
The DCLG will assess whether authorities have improved enough to exit special measures on the basis of their performance in determining applications for which they remain responsible and their performance in carrying out administrative tasks associated with applications made directly to the secretary of state, according to the consultation document.
It adds that the department will also review the steps taken by the planning authority to improve and "its capacity and capability to deal efficiently and effectively with major planning applications".
According to the consultation, the government intends to make initial designations in October 2013 using performance data from the 2011/12 and 2012/13 financial years.
Planning performance and the planning guarantee is available here.
This story was updated after publication to make clear that the government is proposing that councils may face special measures where 30 per cent or fewer major applications have been determined within 13 weeks.