The statement follows Pickles’ comments to a Confederation of British Industry (CBI) event earlier in the week in which he pledged to cut the planning system "down to size".
Summers said Pickles' comments were "not a serious analysis" and failed to offer "new solutions".
The full RTPI statement reads:
"The RTPI deplores the recent ill-informed attack on planning and planners in the run-up to the Budget. It seems to be an attempt to make media headlines and to pander again to some of the more popular myths about the planning system.
"It is not a serious analysis and it fails to offer new solutions to ensure that planning can play an even greater role in boosting economic growth and job creation.
"Planners are also being blamed for delay and uncertainty perhaps to justify Budget proposals for twenty new Enterprise Zones. Yet it was Mr Pickles himself who signed the order revoking the regional spatial strategies (RSS) which has led to the greatest uncertainty in the planning system for a generation leaving developers and businesses hesitant in making much needed investment decisions before confidence is restored.
"A recent cross party select committee report also said the abolition of RSS had directly led to a 'planning vacuum.'
"Any changes to the planning system, however well intentioned, can cause delays.
"We were not alone in our anger with recent reports that senior civil servants have also been outraged by the attacks on the public sector. Local authority chief executives, anyone working for a quango, the teaching trade unions, legal aid lawyers, and public servants generally have also come in for Coalition Government criticism.
"The communities secretary also acts as if planning is just a public sector activity. Our members in both the public and private sectors are committed to delivering growth.
"The RTPI will continue to seek to work with ministers to help produce solutions to problems and to secure a workable planning system in the public interest.
"As every one of our members knows, we will argue that good planning enables and supports economic growth by providing the necessary infrastructure, by allocating land and by working along side various economic development initiatives to enable businesses to expand and invest, as well as supporting communities and protecting the environment."
Pickles comments can be read in full here.