The cabinet is coming under pressure to disclose which organisations lobbied for the abolition of dividend tax after it emerged last week that secret memos had been submitted to the parties during last year’s coalition talks.

The scrapping of the tax on foreign shareholders, which will cost the Dutch treasury €1.4 billion a year from 2020, was one of the most controversial clauses in the coalition deal agreed last year, not least because none of the parties had campaigned on the issue during the general election.

Until last week the government had denied receiving any documents from outside bodies on the dividend tax, but on Friday it emerged that two researchers from the University of Amsterdam had submitted a freedom of information request to see them.

The finance ministry decided that publishing the documents would ‘breach the necessary confidentiality in which informative talks and negotiations take place’  – and so confirmed their existence.

The Telegraaf reported on Monday that economic affairs minister Eric Wiebes had received memos on the subject in a personal capacity, but he declined to say if he had shared them with his colleagues. Labour party MP Ed Nijboer accused the VVD minister of ‘putting up a smokescreen’.

Shell and Unilever

Opposition parties have claimed that the decision to abolish the tax was the outcome of a co-ordinated campaign by multinational firms such as Unilever and Shell and the employers’ organisation VNO-NCW.

Prime minister Mark Rutte described Unilever’s decision last month to locate its headquarters in Rotterdam as ‘very good news’ but denied that it was the sole reason for scrapping the tax.

‘We’re not just doing this because of Unilever. We want to bring as many head offices as possible to the Netherlands,’ said Rutte.

On Friday the prime minister insisted that he had not seen any memos on the subject. Speaking at his weekly press conference, he argued it would be ‘almost impossible’ to form governments in future if documents used in the negotiations were made public.

Opposition parties are now seeking a debate in Parliament this week to clarify how ministers reached their decision. GroenLinks leader Jesse Klaver described the finance ministry’s letter as ‘explosive’ and called on the cabinet to publish the memos.

Klaver pointed out that some economists had disputed the economic benefits of the plan. ‘We want to know why they decided in their wisdom to go ahead with this measure,’ he said. ‘Either they’re lying through their teeth [about the memos] or they weren’t paying attention at the negotiating table and they’ve thrown €1.4 billion down the drain.’