During the 2016 United Kingdom European Union membership referendum, Vote Leave claimed that the UK was sending £350 million to the EU every week (the Institute for Fiscal Studies estimated the true net figure as being about half this.). Following the referendum, the UK signalled that it may consider paying the EU to attain preferential access to the European Single Market and may offer to pay liabilities on a moral and co-operative basis, even if not legally obliged to do so, to secure a preferential working relationship with the EU. In Prime Minister Theresa May's speech on 17 January 2017 setting out the UK's plans to negotiate Brexit, she stated: