The following is directly copied from the Mediapart article linked earlier. We don't get to see the actual "we can do what we want" email just the bolded bit below:
Simon Pearce, a non-executive director at Manchester City, allegedly had another idea: “We could do a backdated contract for the next two years,” worth £5m a year, which “could be paid immediately”. Essentially modifying contracts.
How would the sponsors react to this? Pearce was apparently not worried: “the ones that I have real control over are Abu Dhabi Tourism Authority (ADTA) and Aabar… We can do what we want.”
Shortly thereafter, ADTA’s sponsorship fee goes up by £5.5m, Ethiad’s fee by £1.5m and Aabar’s by £500k. Chumillas writes: “We have decided with Simon Pearce to modify the terms of certain sponsorship contracts with AD (Abu Dhabi).”
An audit that was undertaken at the demand of UEFA in 2014 concluded that the value of the contracts with Manchester City’s four Abu Dhabi sponsors, which made them €140m a year, were worth half according to market value. The sponsors don’t care, according to Mediapart, as it is Sheikh Mansour who is secretly funding them. Already in 2010, Pearce had planned for a £15m contribution from Aabar, before reassuring the firm: “We have discussed it, the yearly contribution of Aabar will be £3m. The £12m remaining will come from another source procured by His Highness.”