In 1793 Mealmaker wrote a pamphlet Dundee Address to the Friends of Liberty that criticised the "despotism and tyranny" of the British government and opposed the war with France. On 12th September 1793 Thomas Fyshe Palmer was arrested and charged with writing Dundee Address to the Friends of Liberty. The authorities claimed that the pamphlet was "calculated to produce a spirit of discontent in the minds of the people against the present happy constitution and government of this country, and to rouse them up to acts of outrage and violence". At the trial, George Mealmaker, gave evidence that he, and not Palmer, had written this pamphlet. Despite this evidence Palmer was found guilty and sentenced to be transported to Australia for seven years.

The British government hoped that the transporting of Palmer and the other leaders of the Scottish Radicals, Thomas Muir and William Skirving, would bring an end to the demands for parliamentary reform. However, George Mealmaker refused to be silenced and continued to campaign for universal suffrage. Mealmaker explained his ideas on democracy in his pamphlet The Moral and Political Catechism of Man (1797). As a result of the publication of this pamphlet, Mealmaker was arrested and charged with sedition. In January 1798 he was found guilty and sentenced to 14 years transportation.

Mealmaker arrived at Port Jackson aboard the Royal Admiral on 21st November 1800. He was no doubt looking forward to being with the other members of the Friends of Liberty who had been transported earlier. However, only Maurice Margarot of the original five Scottish Martyrs was still in captivity. William Skirving, Joseph Gerrald and Thomas Muir were dead and Thomas Fyshe Palmer had finished his sentence and was just about to travel back to Britain.

Governor Philip King was pleased to have a skilled worker in the colony and put Mealmaker in charge of a weaving factory in Parramatta. George Mealmaker died on 30th March, 1808. In a letter written to his wife, Marjory Mealmaker, Lord Liverpool, Secretary of State for the Colonies, claimed that her husband had "suffocated by drinking spirits".