Camilla will cut short royal tour with Charles

The Duchess of Cornwall is to pull out of a royal tour with the Prince of Wales halfway through because she feels it is too "arduous", Clarence House said today.

Charles will spend 10 days visiting Japan, Brunei and Indonesia later this month, but his wife will skip the final four days in Indonesia.

Royal insiders said Camilla insisted she could not cope with a long tour ending in such a hot and humid country.

Her decision to drop out early will once again raise questions about her commitment to her official role and suitability as a future Queen.

The Government has said the tour, which will use chartered flights, is so important in building Britain's relationships with other countries that its vast cost can be overlooked during the credit crunch.

But the Duchess appears happy to leave much of the work to her husband. Critics have labelled her "workshy", noting she carried out a third of the number of official engagements conducted by Charles last year and fewer than half the number undertaken by the Queen.

When Charles and Camilla toured the Caribbean on a yacht in March this year at considerable expense to the taxpayer, the Duchess reportedly complained of "exhaustion" and asked the Foreign Office to introduce more "rest time".

One aide today admitted the Queen, who at 82 is 21 years older than Camilla, continues to do a "remarkable" job.

Clarence House sought to pre-empt any criticism. A spokesman said: " Indonesia is an arduous environment. The programme when they get back to the UK is incredibly hectic." Remembrance weekend is three days after Charles returns to Britain, followed by a week of celebrations for his 60th birthday. "The Duchess needs time to catch her breath,"said the spokesman.