However, with just days before Brits went to the polls, Johnson's campaign director Isaac Levido gave the green light as he was on the hunt for a high-impact video.
The video received millions of views and wall-to-wall coverage in the British press.
Given Johnson's gruelling pre-election schedule, the TG team had little time to make the video.
"As difficult as it was to pull off in 24 hours, we made sure we did a good job of it," Topham told the SMH.
"What we did with Love Actually shows that the most compelling content is creative. If you get the idea right, you don't need data, you don't need targeting. A good idea will sell itself," Guerin said.
The pair were given a pretty free rein on the content they could create for the campaign.
"Isaac [Levido] gave the team a blank canvas," Topham said.
"He was determined for us to be creative whilst sticking to the message, his view was that just because this was the Conservative Party, we didn't have to communicate conservatively."
Johnson did his part in the video in just two takes, according to Topham.
Speaking to the Herald, he said that Johnson pulled it off in a way that "probably only he could have".
Topham and Guerin credited much of their campaign's success to one phrase: "Get Brexit Done".
"'Get Brexit done' was a message that appealed to a broad audience," Topham said.
"Our role as a creative agency was to find new and interesting ways to communicate that message each day."
That message appears to have worked.
The Conservatives were returned with a landslide majority of 80 seats.