By forging closer ties with Hong Kong, Shenzhen hopes to establish itself as a major economic centre in southern China by 2020.

Under the plan, it hopes to bolster co-operation with Hong Kong in finance, logistics and trade.

It also says Shenzhen will jointly review and map out a controversial development plan with Hong Kong over the Lok Ma Chau Loop - a small piece of land straddling the border - and explore the feasibility of setting up a Shenzhen-Hong Kong innovative-industry park.

The plan anticipates that daily cross-border traffic will more than double to 1 million vehicles from the current 422,000.

The blueprint also includes a subtle change.

Previously, Shenzhen planners have pushed the idea that Shenzhen - in combination with Hong Kong - would strive to become an 'international metropolis'.

This latest plan says that through joint efforts with Hong Kong, Shenzhen will aim at becoming an 'international city'.

Xinhua quoted a Shenzhen planner who explained that the change was meant to give Shenzhen a clearer direction and a stronger emphasis on self-reliance.

The new plan to keep Shenzhen at the forefront of the nation's 30 years of economic reforms came after Guangdong party chief Wang Yang urged cadres in the province to 'liberate their minds'.

Shenzhen, which led the mainland in reforms, has struggled in recent years as more mainland cities have made great development strides and have attracted foreign investment.

For Hong Kong, closer ties with Shenzhen could be an opportunity both in terms of market access to the mainland and for tapping the huge developing intellectual-property market across the border.

Shenzhen deputy planning bureau chief Xu Chongguang said it was the first time in three decades that Shenzhen had included such a long-term development strategy in its municipal plans.

Le Zheng , of the Shenzhen Academy of Social Sciences, said the blueprint showed that the idea had become a consensus rather than just wishful thinking on Shenzhen's part.

'It now has a substantial foundation and a chance of being realised because Hong Kong aired similar desires in previous years,' Mr Le said, adding that Hong Kong's agreement 'is the prerequisite for Shenzhen to enlist its neighbour in a strategy for the coming decade'.

Fan Zhongming , a Shenzhen-based member of the China Academy of Urban Planning and Design, said the blueprint would add strategic value to mainland development and help give the country the edge over international competition.

'Beijing's strategy on Shenzhen was unchanged in the past year: to take advantage of its proximity with Hong Kong and exploit opportunities,' he said.

Key targets

The blueprint suggests that Shenzhen should position itself as

An innovative centre

Key city in south China

An international city

Five areas of closer co-operation with Hong Kong

Financial industry

Innovative industry

Service sector

Cross-border transport such as links between airports

Environmental protection in terms of sea, water and air quality