Analysis
Multiple contemporaneous news reports record Dutch Prime Minister Mark Rutte stating, "We must do everything we can to prevent a hard Brexit. The consequences for the Netherlands, for Europe, for the United Kingdom, are simply too great." The quote appears in Reuters and BBC coverage of a press briefing in The Hague on March 30, 2017, shortly after the UK triggered Article 50. No credible source disputes the attribution.
Background
In March 2017, the United Kingdom had formally invoked Article 50, beginning the formal Brexit process. EU member states, including the Netherlands, expressed concern over a 'hard Brexit'—an exit without a trade deal—citing potential economic disruption. Mark Rutte, as Dutch Prime Minister, was vocal in urging a negotiated, softer outcome to protect Dutch trade interests and EU cohesion.
Verdict summary
Mark Rutte did say at a 2017 press conference that the EU must do everything possible to prevent a hard Brexit because the consequences would be severe for the Netherlands, Europe, and the UK.