Lord Mandelson joined forces with a mysterious 'Mr Big' to fight for child predator Jeffrey Epstein as the FBI closed in, devastating new emails suggest.

The Labour grandee appears to have plotted behind the scenes with his paedophile 'best pal' to save him from looming charges of molesting teenagers.

In a fresh cache of damning messages, the now former British ambassador to Washington wrote to Epstein in 2006: 'What's cooking?' after Florida police decided to charge him with unlawful sexual activity with a minor and 'lewd and lascivious' molestation.

Mandelson – at the time Britain's EU Commissioner on a taxpayer-funded £200,000 salary – breezily added: 'Here whenever you need.'

The latest emails, obtained by Bloomberg News, reveal that Mandelson's jaw-dropping 'I think the world of you... you must fight for early release' email, was sent to the convicted paedophile on the day before he reported to prison to start his 18-month sentence as part of a controversial plea deal.