He was appointed a commissioner of the customs in 1671. The same year he was again sent to Holland to replace Sir William Temple, to break up the policy of the Triple Alliance and incite another war between the Dutch Republic and England in furtherance of the French policy. His unpopularity there was extreme, and after three months' residence Downing fled to England, in fear of the fury of the mob. For this unauthorised step he was sent to the Tower on 7 February 1672, but released some few weeks afterwards. He defended the Royal Declaration of Indulgence the same year, and made himself useful in supporting the court policy.