* Romania holds impeachment referendum July 29
* Two-day ballot would harm Basescu drive to defeat vote
* EU criticises Bucharest for recent moves
Romania's suspended president Traian Basescu called on voters in one of the EU's poorest and most corrupt countries to defeat efforts to impeach him, rallying supporters in the Transylvanian city of Cluj on Saturday against what he called 'a coup against the rule of law'.
The European Union has criticised leftist Prime Minister Victor Ponta for his campaign to oust Basescu, his long-time political rival. The issue is due to be put to a national referendum on July 29.
Basescu, whose popularity has plummeted from 65 percent seven years ago to around 10 percent now, found vocal support in Cluj, a stronghold of his ally and former Prime Minister Emil Boc.
Many banners read: "Want a European state led by Captain Basescu" - a reference to Basescu's career as a captain in Romania's communist-era commercial fleet before the 1989 revolution that overthrew dictator Nicolae Ceausescu.
"I ask all Romanians, regardless their opinion, to come and vote," Basescu told a gathering of about 10,000 who braved temperatures exceeding 91 degrees Fahrenheit (33 Celsius) in a central Cluj square. "I'm confident you'll say no to abuse, you'll say no to this coup against rule of law in Romania."
The impeachment attempt is just the latest clash between Romania's two dominant political forces - Ponta's Socialists, the reformed heirs of the Communists led by late dictator Nicolae Ceausescu, and Basescu's Democrat-Liberal allies.
It has rattled markets, sending the leu currency to a record low last week, and raised fears that a country ranked as the EU's second poorest and third most corrupt may be faltering in its march to catch up with the richer West.
Ponta accuses Basescu of blocking government reforms and abusing his post to grant favours to his conservative allies.
On Friday, a day after EU leaders expressed concern over the state of democracy in Romania, Ponta said he had responded in writing to a list of demands from the European Commission.
But he balked at giving a clear signal of whether he would work to undo both an emergency government decree and a separate law scrapping a 50 percent turnout threshold for referendums.
All eyes are now on a tangle of legal statutes that have blurred the referendum rules, most importantly over the turnout.
Basescu would have a better chance of winning with the threshold rule in place, because many in the Black Sea country of 19 million people could stay away, making the vote invalid.
But Ponta's camp are considering extending the referendum to a two-day vote, instead of one, which should increase turnout.
In Cluj, a city of about 320,000 people with a well-preserved historic centre dotted with mediaeval buildings, Basescu's supporters expressed anger at government moves to reduce the power of the constitutional court.
European Parliament head has Martin Schulz dubbed these and changes at other institutions "very dubious".
"We back democracy, it's a shame how this government throws all achievements of the past years in the trash bin. One can't simply sack the president and destroy democracy overnight," said Mircea Stefan, a 64 year-old pensioner, a former mechanical engineer from Cluj.
Elsewhere there were smaller anti-Basescu rallies, including one in Bucharest that attracted hundreds of army officers sacked under an austerity drive backed by the suspended president.
They chanted: "Down with Basescu," and "Go away, Ceausescu calls for you."
Parliament, which is dominated by Ponta's Social Liberals(USL), will discuss the referendum laws on Tuesday and Wednesday and also consider extending the voting to two days.
Analysts said the referendum could still go either way.
"In light of new developments ... and a longer voting period in the referendum, Basescu's chances have fallen steeply," political analyst Cristian Patrasconiu said.
"But we need to remember: Basescu is a formidable sprinter, as when he decided to run for Bucharest mayor in 2000. He jumped from single digits in popularity before announcing his bid to an outright majority at the ballot after just two weeks."