Mr Walker fears the kiln could affect the health of thousands of people in the area, including the 2,000 strong workforce he employs at the food giant's base on Deeside Industrial Park.

Mr Walker's concern is shared by Sir William Gladstone, who has put his comments in writing to county planners.

Sir William's main fear is that burning chemical waste will release poisonous dioxins which could affect the health of pregnant women and young mums.

He say that there can be no iron cast guarantee that filtering systems designed to prevent dangerous material escaping into the atmosphere are watertight.

'Without being alarmist, I think it is true to say that it would be impossible for any pregnant woman or young mother to remain with confidence in the area,' he said.

'In my opinion it would be folly to allow such a kiln in this heavily populated area.

'It is evident that the smallest defect could spread dioxin poisoning, quite apart from the fact that even if the filters are working there will be some escape of highly dangerous chemicals.

'I believe this kind of kiln should be absolutely forbidden except where there are specialists disposing of toxic waste.'

A Castle spokesman said it is concerned a company of Iceland's position should have made this objection based on claims made by CANK - Campaign Against the New Kiln - without at least talking to the cement firm.

'We have contacted Iceland to urge them to withdraw this letter of objection and to meet with us at the earliest opportunity,' he said.