I have 2 dosg - 1yr old lab & 11mth old cocker spaniel. They sleep upstairs with me and can hold their pee/poo all night - 8 or more hrs. I'm out at work for up to 5hrs in the day and they are shut into the kitchen. They are street walked before work and taken to the field after work. They pee/poo freely in the kitchen whilst I'm out. I have washed the floor with doggy floor cleaner and biological washing powder. I have stopped putting newspaper down in case it was just encouraging them to mess. They have toys to play with. I am now considering crating them whilst I'm out as a last resort. Please help!

Crating them is not a bad idea. Usually a dog will not pee or poo in their crate unless they are left in there too long and it is an accident.
If you're leaving them for less than 9 hours they should be fine in crates. Just let them out before you leave.

Maybe you need to adjust their feeding schedule. If you are feeding them to close to the time you leave they may need to go.

I agree, you should crate them while at work. This may be an emotional outlet for them, to express their displeasure with you leaving.

No. no, no I disagree with the above.
5 hours is far to long to be cooped up in a crate!

It is possible that they have some form of separation anxiety.

Also do you give them anything to eat before you go to work?

Do you take them outside and make sure they pee before putting them in the kitchen?

Do you leave any toys for them?

Do they cry when you lock them in the kitchen?

You could try either training them to puppy pads or using some separation anxiety methods...
I'll need a couple more answers before I type that chapter out though ;)