Doncaster North MP, Ed Miliband, and Labour leader, Jeremy Corbyn are set to visit the borough today as part of the party's Remain in the EU campaign.
The past and present Labour leaders are set to deliver speeches at a campaign rally in Doncaster this afternoon on 'why the fight against climate change needs us to remain in the EU'.
Mr Miliband resigned as Labour leader last May following a crushing general election defeat, and prior to taking the party's top job in 2010 he served as Energy and Climate Change Secretary within Gordon Brown's Labour Govenrment for two years.
He has continued to campaign on environmental issues throughout his time as leader and since he returned to the backbenches, and it is thought his experience and views on the subject will help form the basis for his speech today.
"The challenge of tackling climate change is a moral responsibility, an economic necessity and the single most important thing we can do for our children and our grandchildren and leaving the EU would rob us of the ability to overcome that challenge.
"Membership of the EU has not only raised the UK's environmental standards but, especially as I know personally from my time as climate change secretary, enabled Britain to drive progress across all member states.
"Every major climate change agreement has involved EU leadership. So when it comes to climate change Britain stands taller and is stronger inside the EU. That is why people who care about this generational challenge should vote to Remain," Mr Miliband said.
Mr Corbyn, who was voted Labour leader in September, said Brexit would threaten clean beaches and fresh air quality.
He said: "Climate change is one of the greatest fights of our generation, and at a time when the Government has scrapped funding for green projects, it is vital that we remain in the EU so we can keep accessing valuable funding streams to protect our environment.
"Leaving the EU would mean the green spaces, clean beaches and fresh air we want to leave for our children could be at risk. It would risk investment in new green technologies and the jobs that accompany them, and would leave us open to the Tory agenda which has been so damaging to our environment.
"Pollution and climate change don't respect national borders so we can't hope to deal with these issues if we withdraw into our shell. We must vote to Remain and continue to work with our European neighbours to stop climate change and protect our environment."
Britain is set to go to the polls on a referendum over whether we should remain in the European Union on June 23.