Just been reading the laws:
9.4 Watering the pitch
The pitch shall not be watered during the match.
Well, it hasn't been watered, but it has got wet? No grounds for not playing IMO
6.2 Fitness of pitch for play
The umpires shall be the sole judges of the fitness of the pitch for play. See Laws 2.7 (Fitness for play) and 2.8 (Suspension of play in dangerous or unreasonable conditions).
Well, they are playing!!
2.8.2 The Umpires shall immediately suspend play, or not allow play to start or to recommence, if either umpire considers that the conditions of ground, weather or light, or any other circumstances are either dangerous or unreasonable.
My bold: is the change in the condition of the pitch unreasonable?
That whole section actually has arguements for and against?
2.7 Fitness for play
2.7.1 It is solely for the umpires together to decide whether either conditions of ground, weather or light or exceptional circumstances mean that it would be dangerous or unreasonable for play to take place.
Conditions shall not be regarded as either dangerous or unreasonable merely because they are not ideal.
The fact that the grass and the ball are wet does not warrant the ground conditions being regarded as unreasonable or dangerous.
2.7.2 Conditions shall be regarded as dangerous if there is actual and foreseeable risk to the safety of any player or umpire.
2.7.3 Conditions shall be regarded as unreasonable if, although posing no risk to safety, it would not be sensible for play to proceed.
2.7.4 If the umpires consider the ground is so wet or slippery as to deprive the bowler of a reasonable foothold, the fielders of the power of free movement, or the batsmen of the ability to play their strokes or to run between the wickets, then these conditions shall be regarded as so bad that it would be dangerous and unreasonable for play to take place.
2.8 Suspension of play in dangerous or unreasonable circumstances
2.8.1 All references to ground include the pitch. See Law 6.1 (Area of pitch).
2.8.2 The Umpires shall immediately suspend play, or not allow play to start or to recommence, if either umpire considers that the conditions of ground, weather or light, or any other circumstances are either dangerous or unreasonable.
On balance it seems fair to me to be playing but if I was in England camp it would feel 'unfair', regardless of what the laws say.