France and Germany hope Tuesday to round up the magic number of nine eurozone or European Union states willing to back a hotly-contested cross-border financial transactions tax, or FTT.
Almost six months after finance ministers from the 27 EU members crushed a bid to adopt the tax across the single market -- with London to the fore -- Berlin and Paris are back seeking permission to go it alone with a cabal of pioneers.
The issue will top a second day of EU talks in Luxembourg from 0800 GMT onwards.
Monday saw the historic launch of a permanent eurozone rescue firewall, the 500-billion-euro ($630 billion) European Stability Mechanism, dubbed "a milestone" in the battle to end the single currency's three-year debt crisis.
Attempts by the European Commission in June to introduce the tax -- aimed at curbing the market excesses that led to the 2008 global financial crisis -- failed to win enough support among the EU-27, in part due to British concerns over the City of London's future.
Under its provisions, a tax of 0.1 percent would have been levied on share and bond trades, and 0.01 percent on other transactions, generating billions of euros in revenue according to the Commission.
The idea, which has its roots in the 1970s, has been seen as a lasting way to redistribute outsized earnings by banking corporations.
By last weekend, seven EU states had sent letters to the European Commission backing the FTT, which needs the support of nine nations to proceed.
Alongside France and Germany, Austria, Belgium, Portugal and Slovenia had also sent letters by then, with Greece the latest to join the push, an Athens diplomat told AFP. Estonia also is believed to favour the introduction of the tax.
"We've said even though we won't be a part of it, if they get the nine they need, we won't stand in their way," a diplomat from one of the principal blockers told AFP overnight.
But another added: "Once Croatia enters the EU in July, they will need 10 not nine, and even if they get a green light today, it's only for a proposal, opening up the old arguments about how the tax is designed and actually works."
Backers will still need endorsement from all 27 states, by qualified majority vote based on states' respective size and power -- which means getting Europe's No. 1 financial centre of London, as well as other opponents, to approve the precise design of the planned tax.
The Commission last week welcomed the French and German initiative "as a means of keeping up the momentum behind an EU FTT" and urged other member states to "send their letters of request so as to reach this quota."