Prince Charles's private letters become public

Prince Charles's letters will be examined for evidence of pressure put on ministers

On Wednesday, secret letters sent by the Prince of Wales to Labour government ministers are to be published following a decade-long campaign by the Guardian newspaper.

In public - in speeches, on television and through articles - Prince Charles has, for decades, attempted to influence public opinion on matters that he cares passionately about.

But how does he behave in private?

It's a question officials, particularly at Buckingham Palace, would rather wasn't being asked.

It's a question we'll be in a better position to answer with the publication of these letters sent to members of Tony Blair's government.

They'll be examined for evidence of any pressure brought to bear by a hereditary monarch in waiting on elected ministers, and for any evidence that government policy was changed following the prince's intervention.

The correspondence may prove to be benign or may lead people to conclude the future king has been in the habit of overstepping the mark.