SOFIA (Reuters) - Bulgaria's centre-right GERB party on Friday became the second political party to give up trying to form a new government since last month's inconclusive parliamentary poll, bringing the Balkan country closer to a third election this year. President Rumen Radev had asked GERB, the party of former long-serving premier Boyko Borissov, to try and lead the country after the anti-establishment There Is Such a People (ITN), which narrowly won the July 11 polls, abandoned efforts to form a minority government. But with just 63 seats in the 240-member parliament following the July election, just behind ITN's 65, GERB is well short of a majority and other parties have refused to cooperate with it due to public anger over entrenched corruption in the European Union's poorest member state. Before returning the mandate to Radev, GERB's Prime Minister-designate Daniel Mitov, already in campaign mode, presented to reporters a potential list of cabinet ministers so that people can make comparisons and see our potential . This is a potential Cabinet, which we will not present officially because we are in a situation that cannot be untangled by the second mandate... We cannot rely on constructive talks on policy or coalition agreements, he said. Radev must now ask a third party to try to form a government, but political analysts say its chances will also be very limited, following a rift between ITN and two smaller anti-corruption parties. If it fails, as expected, Radev will have to dissolve parliament once again, appoint another interim government and call a new election within two months. Prolonged political uncertainty could hamper Bulgaria's ability to effectively deal with a fourth wave of the COVID-19 pandemic and tap the European Union's multi- billion euro coronavirus Recovery Fund. (Reporting by Tsvetelia Tsolova; Editing by Gareth Jones)