We have a democratic right to protest and we have the right to know what we may be facing. But details are very sketchy.
So far, only one, little-read paper, the "West End Extra" of 6th April has disclosed any details of what the police may be planning. The source (as cited by P Layton a few days ago) is authentic. Whether it is accurate is another matter.
But the "Extra" seems to think that the Met will seek to revive redundant laws from the late 19th and early 20th century, the first banning all political marchs within a mile of the parliament and the other prohibiting 'political uniforms'.
Now almost any left wing activity can be stiched up as a march and almost any unconventinal clothing likely to be worn, as a 'uniform'. It may be that the police will be pouncing on people as soon as they arrive in central London before they can settle and prepare their protests. It may be advisable to avoid all tube stations within that mile of the parliament, and to dress as 'conventionally' as possible to start with.

If of course, You, dear reader, know otherwise, DO write in !