Turkish Prime Minister Tayyip Erdogan inaugurated a $4 billion high-speed train link between Istanbul and Ankara on Friday, the latest in a series of "mega projects" he hopes will help him win a presidential election in a few weeks time, Reuters reports.

Turkey's economic development - driven partly by major infrastructure projects - has been the foundation of Erdogan's popularity despite deepening discontent among his opponents at what they see as growing authoritarianism.

"Twelve years ago, a fast train was nothing more than a dream ... We are now a country which makes its dreams come true," Erdogan said in the western city of Eskisehir where he stopped during the journey, escorted by five helicopters including two Cobra attack aircraft.

"Despite sabotage, obstructions and efforts to slow it down, we have finished this line and are putting it into service," he told a flag-waving crowd, according to Reuters.

The launch - which comes just over three weeks ahead of the presidential election but a year before the line will be fully operational as it currently runs only to the outskirts of Istanbul - was delayed by a few months due to what officials described as sabotage and a test train crash on July 3.

Turkey is constructing a network of high-speed rail links as it looks to ease the burden on increasingly congested highways.

Erdogan's other projects include a 50-km (31-mile) channel to rival the Suez Canal that would render half of Istanbul an island, an airport which Ankara claims will be the world's biggest and a giant mosque atop an Istanbul hill.

The construction of a third bridge over the Bosphorus strait in Istanbul is underway and nuclear power stations are also on the drawing table. Turkey plans to spend $250 billion on roads, energy and IT infrastructure alone over the next decade.

The trains on the new link, made by Spain's CAF and with a top speed of 250 kmh (155 mph), will initially cover the 533-km (330-mile) distance in 3-1/2 hours, significantly faster than existing journey times of between six and eight hours.

The line is planned to link up next year with the $2.8 billion Marmaray rail link below the Bosphorus Strait in Istanbul, the first underwater rail link between Asia and Europe, which Erdogan opened last October.

In the meantime passengers will disembark at Pendik, on the eastern outskirts of the Asian side of Istanbul, some 30 km (20 miles) from the Bosphorus. Those traveling to and from Istanbul city center will for now complete their journey by bus and subway.

The European Investment Bank has provided 1.5 billion euros ($2 bln) in funding for the link, while the European Union has contributed a 120 million euro grant.