Leading scientists, research institutions and patient groups appealed the European parliament on Friday to maintain European Union funding for embryonic stem cell research.

The group said they feared research grants that are currently under review may be threatened by anti-abortion European parliamentarians who want to stop public funding for research involving human embryos.

"European Commission funding must be available to continue to support scientists investigating all types of stem cells - including human embryonic stem cells - with potential to make advances in regenerative medicine," the scientists wrote in a letter released by the Wellcome Trust, a charitable health foundation.

The field could potentially lead to new treatments and cures for a range of debilitating diseases from Parkinson's to cardiovascular and liver conditions, and cutting funding for research involving the use of stem cells would seriously obstruct progress, the group said.

"Many of the conditions that stem cell therapies might treat are neurodegenerative conditions, the prevalence of which will increase with an ageing population (as Europe is facing)," the group said in a press release.

The European Parliament is currently debating the provisions of Horizon 2020, the EU's program for research and innovation which will run from 2014 to 2020.

While draft rules provide funding of stem cell research including embryonic stem cell research, some members in parliament have been lobbying for embryonic stem cell research to be excluded.

Europe, and particularly Britain, is considered a world leader in stem cell research, and scientists said that it is important to continue funding for all avenues of stem cell research if Europe wants to maintain its competitive edge and move closer to the development of new treatments.

The three main types of stem cells that are currently used in research include adults induced pluripotent, embryonic and fetal stem cells. Embryonic stem cells are controversial because they involve harvesting embryos that are just a few days old.

Researchers said that it's still too early to determine which route will be the most effective developing the best treatments for clinical use, so it is essential to keep all research avenues open.

"This field of research is complex.  To enable scientists to best understand the massive potential of stem cells, scientists must be able to continue research in all avenues of stem cell research," the scientists said in a joint statement.

"It is too early to tell which route will be the most effective, for ultimate clinical use, so it is essential to keep all avenues of research open. Any move to make human embryonic stem cell research ineligible for Horizon 2020 funding would risk holding back progress across the entire field."

The joint statement was signed by Association of Medical Research Charities, the British Heart Foundation, the European Genetic Alliances' Network, Britain's Medical Research Council, the charity Parkinson's UK and Wellcome Trust.

"Stem cell research holds a great deal of promise for patients suffering from a broad range of incurable diseases. It's absolutely vital that European Commission funding for this research is maintained. European scientists are leading the way in this field and the first clinical trial of a human embryonic stem cell treatment for a form of blindness has recently received regulatory approval in the UK," Professor Sir John Savill, the chief executive of the Medical Research Council said in a statement.

"To derail such promising science based on the objections of a minority of member states, who do not wish their scientists to carry out this research, would be unwise and unfair, particularly to patients."

"Any scaling back of the EU's investment would send out a dangerous message that could seriously damage this area of research in Europe, to the detriment of patients in the future," Professor Peter Weissberg, Medical Director at the British Heart Foundation, said in a statement.