“Put your money where your mouth is,” a senior EU official warned ahead of a Commission debate and ideas paper setting out the bloc’s options post-2020.
Mr Juncker wants to avoid swingeing cuts to the bloc’s 150 billion euro a year budget, and raise more money to fund security, defence and border management, as well as research and education programmes.
EU sources estimate the bloc’s budget will be 14 billion euros a year worse off after 2020, when the current seven-year fiscal cycle ends and Britain officially exits and stops paying into it.
The EU is seeking to trim future spending on agriculture, which makes up around 40% of the current budget, and regional subsidies (known as “cohesion” spending in EU jargon). It has also mooted an EU-wide plastic tax to help raise new revenues.
The Commission estimates it can save around 100 billion euros by discontinuing regional subsidies to richer countries such as Germany, Denmark, Ireland and the Netherlands, concentrating instead on countries in eastern and southern Europe.
Funding a US-style border and coast guard would cost around 150 billion euros over a seven-year period, an EU official said. The EU currently spends around 4 billion euros securing its borders.
EU leaders – minus Theresa May – will meet in Brussels on 23 February for a first round of talks on the post-2020 budget.
They will be “signalling the EU’s priorities for the next decade”, including stemming illegal immigration, said European Council president Donald Tusk, who will chair the summit.
“We will need to find a balance between funding new priorities and ensuring that the EU’s traditional policies continue, in areas such as cohesion and agriculture,” Mr Tusk said.
Last week Mr Juncker argued against “stupid, poorly thought-through” attacks on traditional budget lines, and said the bloc should seek to make “sensible savings”.
Meanwhile, the EU parliament’s Brexit coordinator has said Boris Johnson’s vision of life after Brexit is the opposite of “liberal”.
Hitting out at the foreign secretary’s widely trailed speech today, Guy Verhofstadt – who leads the Parliament’s liberal grouping of MEPs – hit out at potential future barriers to trade and a return to nationalism.
“Putting up barriers to the movement of trade and people & suggesting that the identity of citizens can only be national is not liberal – it’s quite the opposite,” Mr Verhofstadt said on Twitter ahead of the speech.