2004 Vauxhall Zafira difficult starting in cold wether

Try testing the Glow Plugs or the heater plug relay !! when you get it started does it run lumpy for a short while ?

The heater plugs have been checked but not the hp relay. Will have to investigate. Car runs perfectly once it's started.
Thank's for advice.

sounds like a slight air leak in the fuel system allowing the fuel to seep back towards the tank. when you crank the engine over your priming the system hence the 2 or 3 attempts at starting.
the rubber fuel spill off pipes become brittle in cold weather and may crack. the fuel filter housing is plastic and the temp change could cause the seal to become less effective. i doubt its heater relay as this normally shuts the engine down if defective although always worth having it tested.
another common fault is the copper injector seals, the temp change may be enough for them to loose an air tight seal.
to be honest though, if its starting after 2 or 3 attempts after being sat in a garage for a week or so in cold weather, i wouldnt be too concerned. cheaper supermarket fuel will also cause issues in cold weather due to the higher water content often found in them.