LONDON, July 18 (Reuters) - British Prime Minister Theresa May told her top team of ministers on Tuesday they needed to lead a show of "strength and unity" in the country, her spokesman said.

Weakened by an election last month, May has watched as members of her cabinet brief against each other in the media over Brexit and state spending.

"There is a need to show strength and unity as a country and that starts around the cabinet table," she told her ministers, according to her spokesman.

"She said the government would make better decisions if colleagues were able to hold open discussions but it was vital that discussions in cabinet must remain private." (Reporting by Elizabeth Piper, Writing by Kylie MacLellan)