Fears have been raised that the pledge to give women in England a choice of where they give birth will be undermined by a lack of funds.
Only 2% of births are at home at the moment
From 2009, expectant mothers will be able to choose whether they go to hospital, a midwife-led unit or stay at home to have their children delivered.
But there is not guarantee of extra funds or that staffing levels will rise by as much as experts say they should.
The Tories said there was "no substance" behind the plans.
Labour promised to create greater choice and more personalised services for pregnant women in its 2005 election manifesto.
This included choice of where to give birth and dealing with the same "known and trusted" midwife throughout pregnancy. Although this does not include labour.
Midwives say the government faces a challenge increasing the range of choices in the system as resources are currently stretched with jobs being shed and recruitment freezes in place.
Only 2% of the 600,000 births a year take place at home and research by the Royal College of Midwives has shown that only one in five women is given the option of a home birth in the first place.
There are currently 19,000 midwives working in the NHS, but the RCM says another 3,000 are needed over the next five years to fulfil the promises.
However, Health Secretary Patricia Hewitt said it would be up to NHS trusts to decide on staffing levels, although there would be another 1,000 midwives graduating from training by 2009.
She also admitted no money was being earmarked for maternity services, which currently gets £1.7bn a year, although overall the NHS budget was rising by over 7% in real terms this year.
She said: "Our plan will help create a gold standard of maternity services.
"This will mean that care is designed around the needs of women and their partners."
She also said the NHS needed to make maternity care more of a priority - while the maternity budget has been rising in recent years, the overall proportion of NHS funds spent on it has fallen.
Andrew Lansley, the shadow health secretary, said financial difficulties in the health service were forcing the closure of 43 maternity units this year.
And he added he did not believe that the government would be able to deliver on its promises.
"There is no evidence to support the planned closures and there is no evidence that Patricia Hewitt has substance behind this announcement about home births.
"This is unfair to pregnant women and it is unfair to the professionals."
Liberal Democrat health spokeswoman Sandra Gidley said: "Many more midwives need to be recruited if these plans will ever be more than a pipe dream.
"In the current financial climate, is this really possible?"
Dame Karlene Davis, from the Royal College of Midwives, said she supported the plan, but added: "We are obviously concerned that there will need to be enough midwives to make it happen.
"There are variations across England in terms of the type and quality of service that women receive and we certainly want to see that the government puts in place levers to ensure that this happens for every woman in England and not just the most vocal or articulate women who can receive it."
Professor Allan Templeton, president of the Royal College of Obstetricians and Gynaecologists, added: "If we are to provide mothers with more choice, then this can only happen when our places of birth are fully staffed.
"We will need more consultants and midwives."