Opposition parties GroenLinks and Labour have said they need to secure major concessions from the government before they can support its spring budget plans.

The coalition needs the support of at least one opposition group in the Senate, where it is six seats short of a majority. GroenLinks and Labour (PvdA), who have 14 senators between them, agreed a 15-point joint policy plan in December covering issues such as climate, the labour market and inequality.

Labour’s new parliamentary leader, Attje Kuiken, said the revised budget package ‘can and must be much more social,’ while her GroenLinks counterpart Jesse Klaver warned: ‘We won’t be content with minor changes.’

The two are due to meet prime minister Mark Rutte and finance minister Sigrid Kaag on Wednesday to discuss the spring budget statement, which must be finalised by June 1. Rutte has said that the need to secure opposition support, the worsening economic picture and high inflation have made the exercise unusually difficult this year.

The parties’ bottom line is expected to be an increase of the minimum wage to around €14 an hour, stronger measures to reduce energy consumption and plans to close the wealth gap.

They are also likely to call for the state pension and welfare support to continue to rise in step with the minimum wage.

Those demands come on top of the need to find extra billions to help low-income families pay their rising energy bills, fund extra defence spending in the wake of Russia’s invasion of Ukraine, and repay savings taxes that were ruled illegal by the Supreme Court last year.