Belgium's Finance Minister Johan Van Overtveldt | Emmanuel Dunand/AFP/Getty Belgium gets cold feet on financial transaction tax A split in the government coalition could push Belgium out of EU negotiations on a Tobin tax.

Differences within Belgium's ruling coalition over a European financial transaction tax cast further doubt on the proposal, which is championed by a group of 10 EU states but opposed by the financial industry.

Finance Minister Johan Van Overtveldt exposed the split by saying last week he would "investigate in the coming weeks or months how to put a stop to this tax" because it threatens the economy and the financial sector.

This contradicted the official position of the coalition government headed by Prime Minister Charles Michel from the liberal, French-speaking Reformist Movement (MR). He now plans to underline Belgium's support for the so-called "Tobin tax" in parliament on Tuesday morning.

"The government will stick to the principles as agreed in the coalition agreement," Michel's spokesperson said.

That deal, struck in 2014, states that "Belgium will continue to work constructively on a gradual introduction of a financial transaction tax," but clarifies that it should focus on share- and derivative-trading while leaving the real economy untouched and not affecting pension funds and insurance companies.

However, a spokesperson for Overtveldt — who is from the Flemish nationalist N-VA — underlined his party's "reservations concerning the impact of the tax on the real economy, for instance on pension funds."

The finance minister is eyeing exemptions from the tax to prevent it from discouraging Belgian investors and businesses from taking risks with their capital.

The financial industry has consistently opposed the tax — nicknamed the Robin Hood tax or Tobin tax, after the Nobel prize-winning economist James Tobin who championed it — arguing that it would hurt pension funds and other investors and make it more difficult for companies to raise capital.

Financial industry executives on Monday welcomed Belgium’s skeptical stance, but said that it was unlikely the proposals would be dropped in the near term.

In order for Belgium to withdraw from the Tobin tax entirely, Van Overtveldt and the N-VA would have to convince the three other parties in the governing coalition.

“This is what we hoped would happen and there is a clear direction of travel against the proposal but there’s no guarantee that it won’t happen,” said one senior financial services lobbyist, speaking on condition of anonymity. “There is a lot of political energy and political capital that has been spent on this since the Commission launched the proposal in 2011."

In order to sink the plans entirely, the lobbyist said, a big EU member country like Germany, Italy or Spain would have to come up against it, which looks unlikely at the moment.

Belgian cabinet ministers are expected to discuss the financial transaction tax on Friday. In order for Belgium to withdraw from the Tobin tax entirely, Van Overtveldt and the N-VA would have to convince the three other parties in the governing coalition.

The tax is a long-standing aim of Belgium's mainstream parties but is opposed by the right-wing N-VA.

Belgian Economy Minister Kris Peeters, from the Flemish Christian Democrats who favor the Tobin tax, said: "We shouldn't throw out the baby with the bathwater." He urged Van Overtveldt to negotiate its implementation "in a constructive manner."

Denis Ducarme, parliamentary whip of Michel's liberals, said the party would stand by the plan: “We, as liberals, are very attached to this tax. It’s our way of fighting speculation, to the benefit of the real economy and investments."

The European Commission proposed taxing financial services in 2011, in the wake of the financial crisis. Lacking unanimous approval, an "enhanced cooperation" group of 11 countries agreed to push the project: France, Germany, Italy, Portugal, Spain, Greece, Belgium, Slovenia, Slovakia, Estonia and Austria. Estonia has since withdrawn, arguing that the costs associated with the tax would be higher than the revenues.

Some other countries in the group, such as Slovenia, now appeared reluctant too and the withdrawal of two or more countries would sink the proposal, since EU rules require at least nine countries to back such a procedure.

Belgium has not notified the Commission of any intention to withdraw, according to Commission spokesperson Vanessa Mock, who descried the country as "a very supportive presence throughout the negotiation process."

Francesco Guerrera contributed to this article.