By Jane Elliott
BBC News health reporter
Scientists believe they are on the threshold of a truly significant step forward in the field of medical science.
The aim is to get healthy offspring free
Three months ago, a team at the University of Newcastle was given permission to transfer genetic material from one woman's egg into the fertilised egg of another woman.
They are confident the upshot could be the eradication of certain types of genetic disease.
But they know that a law change is required for their lab findings to be put to practical use.
And they are also aware that anti-embryo research campaigners have set out their stall to frustrate their efforts.
Far from a positive step forward, Josephine Quintavalle, of the campaigning group Comment on Reproductive Ethics, fears the research could result in babies being born with further abnormalities.
Speaking publicly for the first time, Doug Turnbull, the professor of neurology who is leading the Newcastle research, told the BBC News website the whole laboratory was "buzzing with excitement" when they got the decision that they could start work.
He said: "There is such a huge sense of excitement that we can move forward and work. It gives a real buzz to the whole laboratory."
Professor Turnbull said the idea of being potentially help mothers to have children born free from genetic disorders, hopefully over the next decade, was the motivator.
"To be honest that is why we do the research - we believe we can make a difference.
"Those of us who have our own children can imagine what a wonderful thing it would be for them."
But he said all they could do now was to wait and see whether there was a law change.
The scientists say some media reports on their work have been inaccurate and sensational.
But Professor Turnbull and Dr Mary Herbert, head of clinical embryology, are still confident the scientists who make the important decisions about the future development of their work will be fair and dispassionate.
Professor Turnbull said: "The media will say what they want. There has been some sensational headlines and that does not necessarily help form debate, but I don't think it will change the minds of serious scientists.
"I think if our experience with the Human Fertilisation and Embryology Authority (HFEA) is anything to go by then our case will be studied by people who have examined the facts rather than from reading the national press."
Professor Turnbull said it was important that controversial research was properly considered before being agreed.
"It is perfectly logical that these things should be well regulated and all changes should be carefully and thoughtfully considered.
"It is appropriate, if we are going to do this as a treatment, that it is considered by society as a whole.
"I thing everybody is entitled to their views."
A forthcoming review of the Human Fertilisation and Embryology Act 1990 is likely to consider the desirability of using IVF-based techniques to prevent otherwise incurable diseases.
If the review does not result in a law change, then the Newcastle work is unlikely to be of any practical use to potential patients.
Dr Herbert explained: "We have to keep moving to see that the law is changed so that this technique, if found to be without harmful effects, could ultimately be used in clinical practice."
The team hopes to eradicate about 50 or so metabolic disorders linked to faults found in a set of genes located outside the nucleus of a cell.
Collectively, they are called mitochondrial diseases. Mitochondria are the "batteries" that are used to power the cells in all tissues in the body.
About one in 5,000 children and adults are at risk of developing a mitochondrial disease.
Professor Turnbull said the work had often mistakenly been dubbed cloning - but this was not what they were trying to do.
"It is not cloning, it is nothing like cloning," he said.
Dr Herbert said that they had currently been given permission to use only defective eggs.
"If we can see there are not harmful effects we will continue it," she said.
"But babies are a long way off."
However, Mrs Quintavalle is queasy about research she views as meddling with human life, and fears it could create more problems than it solves.
She said: "In an effort to eradicate some diseases you will probably be creating some other abnormalities.
"If you play around at the beginning of life the consequences often only come to light when they are born.
"I think we are so far from allowing these things to take place.
"[The scientists] are whinging that they cannot do the work. Do your research and continue to find out what you can and then come back to the drawing board and see if the public are happy to go ahead."
She said that the scientists had only just been given permission to do the initial work and that it was far too early to be asking for further law changes.
The HFEA said it was unable to comment directly on the forthcoming review, but a spokesman added: "We are looking at the new legislation to provide a clear framework for the future."
A Department of Health spokesperson confirmed that proposals for a review of existing legislation would be published in due course.