By DAILY MAIL REPORTER
It's all over: Matt Smith and Daisy Lowe have split after spending the last 18 months together
They've been apart for most of the summer due to work commitments.
However it appears the prospect of long-term commitment that appears to have caused the breakdown of Matt Smith and Daisy Lowe's relationship.
The Doctor Who actor, 29, is reported to have become 'uncomfortable' at the mention of marriage and called time on their 18-month-long romance.
Sealed with a kiss: Matt and Daisy are pictured together in Capri in June last year
Matt, who plays Doctor Who in the hit BBC sci-fi series, is said to have become increasingly uneasy about settling down and tying the knot with the 22-year-old.
A friend is said to have claimed in The Sun newspaper: 'Whenever engagement and marriage was mentioned he was uncomfortable. He's still a young man and the thought of being tied down was a lot to digest.'
They also said: 'This has come as a surprise to everyone. It was thought they'd be together for a really long time because they were so into each other.
Romance: The couple were together for 18 months before their split this week
'They always seemed so happy together. Matt was besotted with Daisy and she adored him.'
Matt has been busy all summer filming several television projects in the UK, model Daisy has been dividing her time between her native country and Los Angeles, where she recently posed nude for Playboy magazine.
The source added: 'It's really sad that this has happened, but as they're both so in demand at the moment it was really difficult for them to find time together.'
A dog's life: Daisy will no doubt be feeling glum following her split with the actor
Matt pursued Daisy for months before they began dating.
He named the model as one of his dream girls before they had even got together.
A few months before the couple started dating he was asked what he is looking for in his ideal woman, to which he replied: ‘Oh gosh! Daisy Lowe is taken, so that's out of the question. Haha! She's a pretty lady.’
Daisy soon moved Matt into the home she shared with actress Jaime Winstone, but by May this year they had split.
They rekindled their romance two months later in July and they remained as an item from then on.
A spokesman for both Daisy and Matt refused to comment.