Mr Hain was trying to provide leadership, says his office

Federation secretary Richard Eccles, said officers were insulted at suggestions they might not cope with an investigation like the Soham murders.

He accused Mr Hain and Home Secretary Charles Clarke of "desperate tactics".

The Wales Office said Soham was a commonly-used example and Mr Hain had tried to give leadership on the issue.

Mr Eccles claimed policing figures showed the force was performing better than many larger constabularies.

In a letter written to Welsh MPs last month, Mr Hain said the murders of Holly Wells and Jessica Chapman by killer Ian Huntley in 2002, demonstrated the "huge disruption" a major investigation could cause a small police force.

He added: "I have no doubt that, if such an incident were to occur, the smaller police forces in Wales would struggle to manage their resources effectively.

But Mr Eccles said: "I can only assume that Mr Hain is either engaged in a campaign of irresponsible scaremongering or that he truly has no knowledge or understanding of the skills and capabilities of the police officers and staff working across North Wales.

"His comments are an insult to the hard working members of North Wales Police.

"He has chosen a particularly sad and extremely emotive case, in Soham, in an effort to justify his support for the Home Office campaign to impose their will upon Wales".

Very easy

Mr Eccles said the murder of Sophie Hook in Llandudno and major events like disorder at Caia Park in Wrexham in 2003 proved the force was able to cope with demanding situations.

Mr Clarke's merger plans have faced opposition in Wales

He continued: "It is however, extremely sad, that to reach their goal, some are willing to resort to desperate tactics, by raising concerns amongst the general population around the areas of child abuse and murder, this is normally a tactic attributed to the gutter press."

He pointed to the force's performance in league tables compared to larger forces.

Home Secretary Charles Clarke wants to merge Wales' four forces into one all-Wales force despite objections.

A spokesman at the Wales Office said Mr Hain had never intended to single out any of the Welsh forces, and the reference to Soham was a commonly-used example.

The spokesman added that Mr Hain's opinion was drawn from the inspector of constabulary's report.

"We refute there was an accusation against North Wales Police."

The spokesman said it would be very easy for Mr Hain to "sit back and do nothing" on the subject of police force mergers.

But he added: "He feels very strongly that this is the right thing to do and he is trying to provide some leadership on this issue."