Speaking in Liverpool on Tuesday, local time, Burnham delivered an hour-long address that marked a clear departure from his predecessor, Sir Keir Starmer, focusing heavily on domestic issues and left-wing policies.
"I cannot say to you truthfully that where we are is good enough. Brexit has done more harm than good," Burnham said, noting that the EU remains the UK's largest trading partner. He stopped short of calling for Britain to rejoin the bloc, but did not rule it out.
The Prime Minister also became emotional when discussing the future of the United Kingdom, speaking about the influence of his father, who died earlier this month. His comments came just over two weeks after the first ministers of Scotland, Wales and Northern Ireland signed a memorandum demanding a path to independence and, for Northern Ireland, reunification with the Republic of Ireland.
"I'm going to use this job to build the kind of Britain my dad wanted to see and fight with everything I've got to keep it together," he said.
Foreign policy received less than a minute of attention. Burnham voiced support for a two-state solution between Israel and Palestine, said he would be "steadfast" in backing Ukraine and would "stand up to threats wherever they come from, whether Russia, Iran or anywhere." He did not mention AUKUS.
UK Foreign Secretary Ed Miliband said people should not read into the brevity, telling the ABC: "The values that Andy talked about today in his speech are the values that we will apply in our foreign policy."
On artificial intelligence, Burnham said the UK would use its G20 presidency in 2027 to "develop a new global code" to regulate AI, aiming to "capture its benefits" while addressing risks.