Angela Merkel, the German chancellor, and President Macron of France want their nations to speak with one voice in Brussels

France and Germany are to forge shared defence, foreign and economic policies in an unprecedented “twinning” pact regarded as a prototype for the future of the European Union.

Angela Merkel and President Macron will sign a treaty this month to open the way for the neighbours to present a united diplomatic front and act jointly in peacekeeping missions.

Regions on either side of the Franco-German border will be encouraged to form “Eurodistricts” with merged water, electricity and public transport networks. Berlin and Paris will offer cash to incentivise these cross-border areas, which could involve shared hospitals, joint business schemes or environmental projects. Some officials regard these experiments as a petri dish for the integration of the EU.

Both countries will lobby for Germany to receive