The Association of Convenience Stores has urged high street tsar Mary Portas to strengthen town centre first planning policy after revealing there is 30 million sq ft of construction planned for out-of-town developments compared to just seven million sq ft of planned development for town centres.

The ACS met Portas this week to present its research and urge her to take decisive action on the key ­issues affecting independents ahead of the publication of her review of the state of the UK’s high streets at the end of 2011.

“For every town centre development planned, there is currently more than four times as much space being allocated to out-of-town retail,” warned ACS CEO James Lowman. “There is a danger this report will focus on how high street businesses can improve themselves, by asking how they can do better and market themselves better. Those are all relevant questions, but they must not be asked at the expense of the harder issues like planning policy.”

Lowman also called for “radical” changes to business rates and out-of-town parking. “Does the business rate system support town centre businesses enough? The evidence I am seeing is that it doesn’t. It is still far cheaper to operate out of town, when there should be a strong business case to invest in town instead. So business rates in that equation have to be looked at in a radical way.”

He also urged Portas to consider parking charges. “Parking in town is expensive and inconvenient, and parking out of town is convenient and free. We need something to level up the playing field, so we want to make sure that policy makers are taking this issue on,” he said.

However, the BRC said Portas should avoid focusing on one type of retail environment. “It is very important we don’t penalise out-of-town shopping,” said a spokesman. “Recent vacancy figures showed that vacancies in out-of-town are increasing faster than in the high street.”