Technically, we can say no. But our politicians never do. My guess is that they do not want to step on any toes, which could make getting a sweet job in Brussels after their term ends harder.
There are a number of misconceptions regarding 'hide the decline':
1) The "decline" does not refer to a "decline in global temperature" as often claimed. It actually refers to a decline in tree growth at certain high-latitude locations. This decline began in the 1960s when tree-ring proxies diverged from the temperature record.
2) "Mike's Nature trick" has nothing to do with "hide the decline". "Mike's trick" refers to a technique by Michael Mann to plot instrumental temperature data on the same graph as reconstructed data over the past millennium.
3) The divergence of tree-ring proxies from temperatures after 1960 is openly discussed in the peer-reviewed literature and the last two IPCC assessment reports.