The Take That star has tweeted that he will sing at 'milestone' birthdays this year after a series of surprise wedding appearances in 2015.
Supporters have been sending messages of support on social media using the hashtag #singforjenphillips
Dad-of-two PC Phillips, 34, was killed in a hit and run in October 2015 while trying to stop a stolen Mitsubishi pick-up truck driven by teenager Clayton Williams.
Announcing his planned performances, Gary tweeted: “2015 was the year I sang at Weddings ! And what fun we had ......
“If you have a ‘milestone’ Birthday this year start your campaign now !
“21, 30, 40, 60, 110 !!!!! I’ll come and sing at your party.”
@bogstandardblue has been leading the calls on Twitter, saying: “I NEED you all to retweet this
@GaryBarlow jen phillips turns 30 this year, without her husband. #SingForJenPhillips”
The post has been retweeted 660 times since Wednesday.
One supporter, Karen Newton, Gary Barlow urged to sing at 30th birthday party for widow of PC Dave Phillipswrote: “Nobody more deserving of this xxx”, while Katherine Heyes said: “with what that lady has been through she deserves it too”.
Earlier this week Gary revealed his first milestone birthday appearance was already in his diary, but did not give any clues about the lucky recipient.