Zac Goldsmith, MP for Richmond Park and North Kingston, will join representatives from Prospect, PCS and GMB  to hand in the petition, which is about to exceed 100,000 signatures.

Mr Goldsmith, whose constituency is home to Kew Gardens, said: “It’s not clear to me that Kew Gardens can sustain its extraordinary work with the level of cuts being imposed.

“Kew Gardens is a national jewel, and it would be a tragedy if its work and reputation were to suffer as a result of excessive cuts.”

Prospect negotiator Julie Flanagan said: “Successive independent reviews of Kew have praised the quality and value of its scientific work and recommended that its public funding be maintained or increased.

“Kew has already lost approximately 50 posts, vacancies are not being filled and management is planning the loss of a further 50-70 posts.

“Cutting staff reduces Kew’s capacity to fulfil its statutory obligations, to carry out its leading science and conservation, and to generate its own revenue.

“It has been heartening to see how much people from across the globe recognise and support Kew’s value. It’s a tragedy that the coalition government can’t do the same.”

Kew maintains the world’s premier plant and fungal collections, including 30,000 living plants, one billion seeds and the DNA of 20 per cent of the world’s plant species. Without maintaining and developing these collections and expertise, the UK’s position as a world leader in plant conservation stops.

Kew announced a £5m deficit for the year and plans to axe about 125 science and public engagement staff in March 2014.

The job cuts come after a steep reduction in Kew's public funding from the Department for Environment, Food and Rural Affairs first announced in 2010 and imposed year-on-year since.

Other supporters include:

• Alan Titchmarsh, who said: “As a former student and member of staff at Kew, I recognise its unparalleled role in terms of research and the custodianship of an unrivalled plant collection. It simply cannot be allowed to suffer irreparable damage.”
• Sir Ghillean Prance (former Director of Kew): “The scientific work of Kew is vital for the future of biodiversity and for climate change studies.”
• James Wong: “This puts UK national food security, drug development and climate change prep at genuine risk. Kew is a vital scientific and genetic resource, not just a ‘pretty garden’.”

• The petition is at: http://bit.ly/save_kew

  http://kewcuts.org

  Twitter: @KewCuts

  Facebook: Stop Kew Cuts

  Hashtag: #kewcuts