Stean Wagstyl:

But she defended diesel and backed the industry, saying it had a key role in the economy and required support as it responded to technological change, not just with electric cars, but self-drive vehicles and car-sharing systems. And she pledged government backing for innovation saying: “Where companies cannot manage it alone, the government must stand behind them and push things along.”

The chancellor rejected a proposal made last week by Mr Schulz, as he tries to revive his flagging election hopes, for a quota for electric vehicles. She questioned whether quotas could be effectively implemented across the EU.

On economic policy, Ms Merkel went out of her way to appeal to SPD voters with a powerful defence of Germany’s “social market” economy, where market forces are balanced by social intervention.

She took some credit for the minimum wage, introduced by the SPD in the current coalition, saying it had brought many workers “more security”.

She also backed concerns, first raised by trade unions, about contract workers supplied to employers by agencies. She said flexibility had to be matched by protection for the people involved.

Ms Merkel did not once mention Mr Schulz or overtly attack the SPD, in a classic display of the “assymetric demobilisation” approach she has used in previous elections in which she deliberately avoids goading the opposition into action. Instead she three times praised Franz Müntefering, a former SPD finance minister in a Merkel-led coalition, who in 2009 authored plans for raising the retirement age from 63 to 67.