Leah McFall on course to win The Voice

Leah McFall made the top five in the iTunes chart with I Will Survive

Leah McFall is the bookies' favourite to win BBC talent contest The Voice following the semi-finals this weekend.

McFall, 23, who is mentored by Will.i.am, won the public vote over fellow Team Will member Cleo Higgins, to join Matt Henry, Andrea Begley and Mike Ward in next week's live final.

Last week, McFall made it into the top 20 of the official UK Charts with her performance of I Will Survive.

With odds of 2-7, Coral bookmakers said "she only has to show up" to win.

The final, which takes place next Saturday, will be decided entirely by public vote.

Each artist will perform a song of their choice, as well as performing a duet with their mentor. The act with the lowest number of votes will then leave the show, before the remaining three perform their favourite song from this series.

The winner wins a 'lucrative recording contract'.

"I rarely come across people like Leah," said coach Will.i.am at the semi-finals, citing her "incredible range and crazy work ethic".

McFall, from Belfast, sang Killing Me Softly for the live semi-finals, as well as performing a group song, Rapture, with the Black Eyed Peas frontman and Higgins.

Begley - McFall's closest rival - is coached by The Script's Danny O'Donoghue; country-singer Ward is coached by Sir Tom Jones; and Henry is mentored by Jessie J.

'Most-watched programme'

The concept behind The Voice originated in Holland in 2010, and the TV show has since become a worldwide brand, rivalling hit series such as The X Factor and American Idol.

The second UK series began in April on BBC One, and saw a steady rise in ratings throughout the blind auditions, peaking at 9.57 million viewers.

However, ratings have since fallen, with last week's quarter-final seen by an average audience of 4.2 million.

Saturday's semi-final, which ran from 19:00-21:10 BST, bucked the downward trend, drawing an average audience of 5.8 million, approximately 28% of the available audience, according to overnight estimates.

At the show's peak, it had an audience of 6.7 million; the BBC said it was the most watched programme of the night.

It was also a marked improvement on the 4.5 million who tuned in for the semi-finals last year.

Sir Tom Jones's pick - Leanne Mitchell - won the first series of The Voice UK last year, but failed to break into the Top 100 with her debut album.