Mrs Merkel’s future may come down to how well both the CDU and its main coalition partner, the centre-Left Social Democrats (SPD), perform at the ballot box. If the SPD does badly it could withdraw from her coalition and force new national elections or a change of chancellor.
Mrs Merkel’s decision to sit out the European campaign is a blow to Manfred Weber, the lead candidate of the powerful European People’s Party bloc (EPP), to which the CDU belongs.
Mrs Merkel is one of Mr Weber’s most important backers in his bid to become the next head of the European Commission.
“She is campaigning. She is campaigning with me throughout Europe,” he insisted to Bild newspaper. “She has decided in consulation with us that the party leaders should carry the campaign in Germany.”