The latest waiting lists show the total number waiting for treatment in April rose to 1,093,000. The number waiting more than 12 months for treatment rose from 46,800 in March to 48,000 in April.
The increase is a blow to the Government, which has invested millions of pounds in driving down NHS queues. Those initiatives have been attacked by the medical profession for distorting clinical procedures in an attempt to meet targets.
But Mr Dobson has already met one pledge to reduce waiting lists to below the figure inherited from the Tories. The lists are 65,000 below pre- election levels and within 35,000 of a manifesto pledge to cut the number of people waiting by 100,000 by the next election.
Mr Dobson said: "As we know, NHS staff had a hard time over Christmas and New Year, yet in the first three months of this year their unstinting and dedicated work reduced waiting lists by 100,000."
He added: "After three months of uninterrupted hard work many of the staff involved took a well-earned break at Easter - and quite right too. Some hospitals also took the opportunity to carry out maintenance work on operating theatres, so the lists went up in April."
Dr Peter Hawker, chairman of the British Medical Association's consultants committee, said: "It would be outrageous to suggest that an upwards blip in the numbers should be blamed on doctors taking an Easter break. The root problem is a shortage of doctors and in some hospitals, a shortage of theatre facilities and intensive care beds and staff."
He added: "These cannot be fixed by short-term waiting list blitzes. It requires sustained investment and consultant expansion."
Research published yesterday shows hospital death rates are lower if there are more doctors per patient. Britain has one of the worst ratios of doctors to patients among 29 industrialised nations, with just 1.6 medics per 1,000 people compared to 6.1 per 1,000 in Switzerland, 5.5 in Italy and 2.6 in the United States.
The shadow Health Secretary, Ann Widdecombe, said: "Labour's failure of our health service is clear for all to see now that waiting lists have actually risen, despite all Frank Dobson's complacent boasts that they were about to meet their political pledge.
"Despite Mr Dobson's desperate attempts to meet his pledge, which has resulted in a massive distortion of clinical priorities and a resulting deterioration in standards of patient care, today's figures show that even his catalogue of fiddles cannot rescue him any more, and nor will his pathetic excuse for this rise be believed."
The Liberal Democrat Health spokesman, Simon Hughes, said the Government was now feeling the effects of having set the wrong target.
"It should have been waiting times not waiting lists. It hasn't been an early pledge redeemed and it was a ridiculously modest target anyway."