Fears rose today that vulnerable people could have to wait for their flu jab after the Government confirmed stocks would arrive late.

The jab is usually given to high-risk groups first, including the over-65s, people with respiratory conditions like asthma, and those with chronic conditions like diabetes.

Earlier this year, manufacturers were forced to switch to growing a flu strain for the vaccine called 161B after another strain, Wisconsin 161, failed to grow.

That has resulted in delayed deliveries to GP surgeries.

Today, the Department of Health said the situation was better than it predicted in June but warned that some surgeries in England would have to share their stocks.

The Department has ordered 15.2 million doses for across the UK - around a million more than last year.

It said there should be enough doses in the long-term but some patients would have to wait.

A shortage last year led to a row after the Government claimed GPs were giving flu jabs to the "worried well", instead of prioritising at-risk groups.

By the end of this October, GP surgeries will have received more than 9m doses, and a total of 13m doses by the end of November.

The full delivery of 15.2m doses should be completed by the end of December, the Department of Health said.

Those figures compare to last year's when 2m doses were delivered by the end of September and 10.5m by the end of October.

Dr David Salisbury, director of immunisation at the Department of Health, said GPs would have to match supply and demand.

They would be helped by local flu co-ordinators to "iron out feast and famine" at a local level, he said.

"Practices that were late putting in their orders are not going to be at the front end of the queue in getting their deliveries.

"We want them to be sure that they are using their vaccine wisely so that people who have got clear risk factors are the ones they are bringing in according to a priority list we sent out earlier this year."

Dr Salisbury said the Government could not give assurances that everybody who needed a vaccine would get one in October.

He recommended that patients call up their surgery and ask about availability.

"Some people will have to wait but there will be a vaccine for them," he added.

There are fears that an early flu season could leave thousands without protection from the annual jab.

"That's a situation that we face every single year," Dr Salisbury said. "It's not predictable as to when the influenza season will be."

Last year, 75.3 per cent of those aged 65 years and over in England received the vaccine - the highest number ever.

There was 50% coverage of priority groups aged under 65 - a rate the Government wants to see improved this year.

People having the jab take 10 days to build up a good level of protection.

The British Medical Association (BMA) said surgeries faced a challenge to immunise everybody and asked patients to wait to hear from their doctor rather than pick up the phone.

Dr Hamish Meldrum, chairman of the BMA's GPs committee, said: "Late delivery of vaccines means immunisation clinics will in many areas start later than normal.

"While most practices should get supplies in October and November, we have heard of some practices having to wait until December.

"It will be quite a challenge for surgeries to immunise all their at risk patients before the winter flu season sets in.

"For some it may be impossible and we will have to hope for a late onset of the annual flu outbreak.

"There certainly won't be spare supplies to provide jabs for those not in the at-risk groups.

"Patients over 65 and others in at risk groups can help avoid adding to the workload by resisting the temptation to ring up and ask when flu jabs will be ready.

"GPs know who their at-risk patients are and will contact them when their vaccines supplies are available.

"It really will help us to carry out the job of protecting patients from the effects of flu if patients follow the adage - don't ring us, we'll contact you."

Dr Lorna Layward, research manager at Help the Aged, said it was "extremely worrying" that at-risk groups may not be able to get their jab early.

"If an older person develops flu before they can get their jabs, the consequences could be potentially life-threatening," she added.

"The Government needs to act urgently to ensure that the most vulnerable people get their vaccinations early in order to prevent unnecessary deaths."

Amanda Eden, Diabetes UK care advisor said: "People with diabetes are a high risk group when it comes to the flu and by not getting the flu jab, they are open to the threat of health problems.

"Diabetes UK would urge everyone with the condition to have the flu jab to ensure they don't become poorly this winter."

A spokeswoman for Asthma UK said it was estimated that 80% of asthma attacks in children and 60% of asthma attacks in adults are caused by respiratory viruses.

"We hope the late delivery of the flu vaccine does not impact on people with asthma who find colds and viruses trigger their asthma symptoms," she added.

Cold weather can kill up to 20,000 people a year in the UK, rising to 40,000 in particularly cold winters, with thousands of deaths attributable to the flu.

The at-risk groups, in order of priority for the flu jab, are:

- Those aged 65 and over

- Those with a chronic respiratory disease like asthma

- Those with chronic heart disease

- Those with chronic renal disease

- Those with chronic liver disease

- Those with diabetes

- Those with a compromised immune system and those living in long-stay residential care homes or long-stay facilities.