Caravan fridges normally use the Absorption process to cool the fridge. The fact you mention using Gas and Electricity tells me your fridge is one of these. They have a limited ability to cool so when ambient temperatures are high, these fridges can struggle. Check the specification of your fridge for its maximum ambient temperature.
When you tell us "main part still warm running on gas and electric " Do you mean you are using both gas & electricity do you mean your using both power sources at the same time? If you are, you may be adding extra heat to the back of the fridge, and that might be compromising its performance. Try with just one fuel source at a time... Sometimes more (heat) isn't always going to mean better cooling.
As has been mentioned in other answers, some people who regularly caravan in high temperatures fit fans to the fridges exterior vents to increase air flow through the condenser panel at the back of the fridge.