The former Eastenders star, 28, has been dating Artem, 29, since they met on Strictly Come Dancing last year.
It's claimed he has moved out of their home and gone to stay with friend Robin Windsor as sources close to the pair say things are strained between them.
A source said to UK newspaper The Sun: 'They've been having a terrible time together and decided they needed some space. Artem left their new home and skulked off to Robin's.
'The stress of the show has been getting to Artem as it's a tough gig with numerous rehearsals that fill up his day. They're a very passionate couple so when things flare up, they tend to flare up in a big way. Everyone is worried that the relationship is now doomed.'
It's claimed Kara has been jealous of Artem rehearsing for the new series of the show with Holly Valance, who is his partner this year.