Ed Sheeran says he has received encouragement from other singers, as he faces the second week of a copyright trial alleging he ripped off iconic Marvin Gaye hit Let's Get It On in his song Thinking Out Loud.

The 32-year-old star, who denies copying the hit 1973 soul track which was written by Marvin Gaye and Ed Townsend, has so far spent two days in the witness box at the Manhattan federal courtroom in New York.

Sheeran said he has heard from other singers since the trial began last week because they share his worries about litigation resulting from their own songwriting.

The Suffolk-born star did not identify who the singers in question were, but said they are cheering him on - grateful that he is standing up against what all songwriters view as a threat to their work.

"When you write songs, somebody comes after you," Sheeran said.

He has so far offered a spirited defence of his work, and both sung and played the guitar for the Manhattan courtroom.

In the first week of the trial, Sheeran gave a brief mini-performance of his hit Thinking Out Loud, which reached number one in 2014 in more than a dozen countries, including the UK, US and Ireland.

The prolific artist has said he uses his own version of phonetics to create songs quickly, saying he is able to write up to nine songs a day.

The trial stems from a lawsuit filed by Townsend's daughter - Kathryn Townsend Griffin - several years ago, seeking unspecified damages.

A video clip, filmed at a concert in Zurich, in which Sheeran can be heard segueing on stage between Let's Get It On and Thinking Out Loud, was described as a "smoking gun" by Townsend's lawyer during opening statements.

Sheeran has said he uses "mashups" (switching from his song to somebody else's and back again) to "spice it up a bit" during concerts, generally choosing songs that utilised similar chords.

He also told the court that Thinking Out Loud had been previously referred to as "the Van Morrison song" by his record label, calling the Northern Irish singer "one of the most important influences in my life".

Sheeran, who didn't attempt to hide his irritation during cross-examination, has said he finds it "insulting" that he is being accused of stealing other people's songs.

Last year, Sheeran won his High Court copyright trial against two songwriters who claimed he ripped off part of one of their songs for his huge 2017 hit Shape Of You.

At the time, Sheeran said such copyright claims were "way too common" and "made with the idea that a settlement will be cheaper than taking it to court, even if there is no basis for the claim". He said such cases were "really damaging to the songwriting industry".

The trial, which is expected to last two weeks, continues.