‘Say it to my face’ says Kamala Harris as she again challenges Donald Trump to debate – as it happened

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Kamala Harris's campaign has announced a $50m advertising blitz ahead of the Democratic national convention next month with a television ad that portrays the presumptive Democratic nominee as fearless".

The 60-second ad will be the first in a series of paid media efforts ahead of the convention, which begins 19 August in Chicago.

We believe in a future where every person has the opportunity not just to get by, but to get ahead. Where every senior can retire with dignity. But Donald Trump wants to take our country backward. To give tax breaks to billionaires and big corporations and end the Affordable Care Act. But we are not going back.