Pressure, as everbody who reads the newspapers knows, is either mounting or growing, especially on ministers (government not religious). I have searched but can find no mention anywhere in the British press of pressure descending or dwindling. Indeed, I imagine the cabinet room to be rather like the Mariana Trench and its ministers to resemble the angler fish and flounders that haunt those remote and inhospitable depths. Geoff Hoon, I am reliably informed, is able to withstand pressures of up to 15,700 pounds per square inch, which would crush a normal human in an instant. It's something to do with being from Nottingham.
The mechanism by which pressure mounts is almost always a thing called a ratchet, which is used as part of the phrasal verb "to rachet up". This strange process has been reported 620 times in the last week alone. Neither Barack Obama nor Mahmoud Ahmadinejad nor Rafael Benitez seems ever to leave home without his trusty ratchet. A ratchet is of course "A mechanism consisting of a pawl that engages the sloping teeth of a wheel or bar, permitting motion in one direction only." It looks like this (the pawl is the bit at the top):
The wheel can only turn anticlockwise. This device is the reason that pressure only ever mounts and grows: the pawl is stopping it from declining. This is bad news for Geoff Hoon. It's odd that journalists' imaginations should always leap to this reasonably obscure mechanism, I assume that they're all terribly keen on DIY. Many other things can be ratcheted up including sanctions, salaries and capital buffers (the people who polish London).
A capital buffer working on Nelson's Column