By Fatos Bytyci

PRISTINA (Reuters) - Kosovo's drivers are in uproar after an administrative slip-up led to the country running out of new license plates, forcing it to issue paper substitutes that are mostly invalid abroad.

The paper plates, around 10,000 of which have been issued, are accepted only in tiny Kosovo, a predominantly ethnic Albanian country which broke away from Serbia in 1999, and in neighboring Albania.

Further obstacles to travel are the last thing the impoverished and isolated country needs as its 1.8 million citizens, many of whom work abroad, struggle to drum up business around the world.

"I was supposed to go to Belgrade today to apply for an Indian visa but I can't go with my car," said Tefik Maliqi, 60, a businessman.

Campaigners blame corrupt public procurement practices for the failure to source metal plates. Bidders in the failed tender to manufacture new license plates complained of an opaque and irregular process.

"I paid 15 euros ($16.80) for paper plates and can't go anywhere with them. Someone in the government should resign over this," said Samir Fejziu, 38, pointing to his rain- and mud-spattered plates.

Since formally declaring independence in 2008, Kosovo's economic development has been slow, with the European Union and the World Bank blaming corruption and isolation for its sluggish growth.

(Editing by Thomas Escritt and Mark Trevelyan)