Gwen Stefani and Blake Shelton's relationship has been "stretched to the limit" during quarantine

The source told Us Weekly magazine: "They feel suffocated and stressed. They're both stretched to the limit."

It has also been reported that the issues between the couple are a result of them moving into a new family home in Los Angeles.

The insider added: "Friends say this move has turned into a nightmare. This is the toughest period they've had so far without a doubt."

However, the source admitted there is hope for Gwen and Blake, as they have previously found ways to "work through any tension and look at the bigger picture."

The insider said: "They know how to compromise."

The couple - who have been dating since 2015 - finally moved into their new home in Los Angeles earlier this month after buying the property in 2019.

Gwen was reportedly keen for her kids - Kingston, 14, Zuma, 12, and Apollo, six, whom she has with ex-husband Gavin Rossdale - to move in ahead of the new school year.

A source shared: "They are very happy to be settled at last in their family home.

"Gwen wanted to be moved in for the start of the school year, even though the kids are doing school at home because of COVID-19."

The 'What You Waiting For?' hitmaker and Blake each have a room to themselves in their new pad.

The insider said: "Gwen has a glam closet any woman would love to have. And Blake's closet isn't so shabby either."