by Brian Wheeler BBC News Online business reporter

Plans to build hundreds of thousands of new homes in the south-east of England are unlikely take the heat out of the booming property market, estate agents have warned.

It will generate headlines but it will have little affect on the housing market John Wrigglesworth, property consultant

John Prescott gave the green light in February for a string of developments across the region.

The deputy prime minister has said he wants to ease a chronic housing shortage and provide affordable homes for key workers such as teachers and nurses.

But opinion is divided over whether his plans will have any real impact on property prices - or provide much-needed relief to first-time buyers priced out of the market.

'Too late'

Property consultant John Wrigglesworth said: "It will be akin to putting snowflakes on ice cubes.

If they are not careful they could be building the slums of tomorrow Graham Harris, estate agent

"It is too little, too late. It has been dragged out for far too long.

"It will generate headlines but it will have little affect on the housing market, because it is spread out over too many years."

London estate agent Graham Harris said he thought Mr Prescott's proposals had "not come a moment too soon".

"It is already five years too late, let's get on with it," he told BBC News Online.

"The (housing) market will absorb it very comfortably, although it must take the steam out of one sector of the market in particular.

"It will help young couples trying to get on the property ladder."

Pre-fab fears

But there is also concern that some of the affordable houses will be pre-fabricated, raising fears of 1960s-style slums.

I don't think they have thought it through properly Melfyn Williams, National Association of Estate Agents

"We need to know more about what these things are going to look like.

"We need to know now what these plans are.

"If they are not careful they could be building the slums of tomorrow," warned Mr Harris.

The rapid increase in house prices in the south-east, which has seen a 25% increase in recent months, was largely down to a shortage of properties, he added.

So any new development would be welcome.

Green sites

But Melfyn Williams, president elect of the National Association of Estate Agents, was more sceptical about the government's proposals.

"I don't think they have thought it through properly.

They need to aim more UK wide, they don't need to just focus on one corner of the British Isles," he said.

He added: "It doesn't help the UK as a whole and its social and economic problems.

"They are just taking away green sites."

'Dormitory towns'

He was also concerned there would not be enough genuinely affordable housing to make a difference to first-time buyers.

Because the new developments are planned over 30 years, the increase in supply will not be enough to have any real effect on property prices, he added.

Meanwhile, John Calcutt, chief executive of housebuilders Crest Nicholson, warned of the need to make the new developments economically independent.

"If you are not going to attract new industries, new business, into these depressed areas, what you are going to have is dormitory towns for London, which is what you don't want."

He said the key to making the new developments sustainable was transport infrastructure.