European governments argued through the night in a bid to agree a deal on tightening the oversight of eurozone banks, hours before leaders stage on Thursday their final summit of a gruelling third year in debt-crisis mode. After 12 hours of talks at around 0130 GMT, European Union finance ministers had found ways to overcome many of the host of divisions between countries big and small, and over which banks would be covered by which supervisors. Seen as key to taming the debt crisis and putting the bloc back on track, this first step towards a hoped-for \"banking union,\" agreed by European Union leaders in June, could be followed by a formal accord at a two-day summit starting Thursday. The timescale for implementation remains unclear -- some suggesting March 2014 would now be the earliest date, whereas the impression created in June was that a radical system would begin in January 2013. That was also to have been followed up with further banking-market integration, including an EU-wide deposit guarantee scheme -- although the prospect of that goal had already slipped beyond the horizon. Still, the upshot, according to the European Commission spokesman for financial services, was that enough of an agreement had been found for leaders to be able to say they had reached a common jumping-off point at their summit meeting on Thursday. Negotiations have been pencilled in for next Tuesday with the European Parliament, although there remains ample scope for fresh problems as the incoming Irish EU presidency takes the draft legislation forward over the coming six months. EU leaders want to tighten supervision as a condition for the bloc\'s bailout fund to be able to step in and directly recapitalise banks, instead of passing rescue funds through governments which adds to their sovereign debt loads. Both Germany and France said they believed a breakthrough was possible. Even if details remained to be worked out, German Finance Minister Wolfgang Schaeuble said: \"I am confident that we find a solution on the banking supervision in time for Christmas.\" \"The parameters of a deal are there, it\'s within reach,\" French Finance Minister Pierre Moscovici told AFP. Britain, which will not be joining the new regulatory club, wanted special voting rights that would protect the City of London global financial centre, and officials in Chancellor of the Exchequer George Osborne\'s entourage appeared happy with the guarantees obtained. Osborne himself said London had \"a huge interest in this banking union working properly ... It\'s in everyone\'s interest that we have a better working banking system in Europe.\" Finance Minister Anders Borg of Sweden, also staying out of the euro, was as ever a firm backer in the argument about restricting the scope for the European Central Bank, which speaks for the 17 eurozone states, to dominate contentious decisions affecting non-euro states. Aspects of these and other rows, such as how much money banks need to have on their books to come under the ECB\'s gaze, will likely resurface, with the new watchdog still needing parliamentary approval in key countries such as Germany. Among side issues at these talks, Berlin and Paris signalled that Greece had managed to rub out enough of its debt in a so-called \"buyback\" to expect final approval on Thursday on the release of some 40 billion euros ($50 billion) in long-blocked bailout loans. It also emerged that the conservative group in the European Parliament, the assembly\'s largest, had invited former Italian premier Silvio Berlusconi to party talks in Brussels on Thursday. Berlusconi\'s party last week ended its support for Prime Minister Mario Monti and said he would run for office, for the sixth time in the last 20 years. Berlusconi sowed confusion Wednesday by saying he could abandon his re-election bid if Monti decides to run.