Dr Mark Tester is a researcher in Plant Sciences, and until 2003, head of the Laboratory of Stress Physiology, University of Cambridge.
He has been extensively quoted in the British media as an example of the demoralised hordes of scientists being driven from the country because of the anti-science atmosphere in the UK, for example:
One signatory [to the Sense about Science open letter the the British Prime Minister] is Mark Tester, head of plant science at Cambridge University, who is heading to the Waite Institute, Adelaide, in search of a safer environment and better funding. He said: "Industry has left in droves and that reduces the options for researchers and students." 
What most of the news reports do not mention is that although Dr Tester does certainly perceive a "negative dimension" in the British attitude to GM science, he says his main motive for returning to Australia (he is a graduate of Adelaide University) is that he was "pulled" rather than "pushed": he has been headhunted by the Australian government with the lure of a AUS$230,000 salary. This comes from a Federal fund designed to attract academics (back) to Australia.