LIZZIE Deignan knows she must be "prepared for anything" as she looks to successfully defend her Women's Tour of Britain title.

Riders are set to face the longest and hardest edition of the event to date this week ahead of what promises to be a spectacular finish on the streets of London.

On Sunday, the capital will host the finale for the first time in the race's history, with a 62km blast around the streets set to culminate in a sprint finish on Regent Street St James's.

But to get there, the peloton will need to tackle a series of long days in the saddle starting today in Northamptonshire – with three of the five stages around 150km in length.

Whoever is in the race leader's green jersey by London will have been made to earn it, with Britain's former world champion Deignan starting out as favourite after taking overall victory in 2016.

She had taken over the race lead with victory on stage three in Chesterfield and the Derbyshire town could again prove decisive as the start and finish venue for stage four, which takes the riders through the Peak District.

After coming through a difficult period – when she faced questions over missed anti-doping tests in the run up to the 2016 Olympics – Deignan secured a hugely impressive win in the Tour de Yorkshire when she last raced on home roads in April.

The 28-year-old from Otley has the powerful Boels-Dolmans squad behind her but is taking nothing for granted.

Deignan said: "It is about expecting the unexpected in this race. You can't ever lose focus here because there is always something around the next corner. I am prepared for anything.

"I went back to basics in May. I didn't race and I did a load of base miles again. In terms of speed, I may not be the fastest here, but I am looking to use this race as preparation for the nationals."

Deignan is relishing another opportunity to lead a British success on home soil.

She said: "It has developed into a race that everybody targets. I am not very good at stage races normally (but) having the home crowd and a very strong team helped me achieve that victory last year."

Yet Deignan will face competition from the likes of previous winners Lisa Brennauer (Canyon/SRAM) and Marianne Vos (WM3 Pro) as well as Ashleigh Moolman-Pasio (Cervelo-Bigla), who finished runner-up last year.

Boels-Dolmans team-mate Anna van der Breggen, the reigning Olympic and European road race champion, will also be out to make an impact.

The Dutchwoman said: "We don't have many stages races and those that we do have been on the calendar for many years, so it's really cool to have this new event develop at such a high level.

"I have done some good training. I want to have some fun here, I want to do good for the team and make myself ready for the nationals."

British squad Wiggle High5 will, meanwhile, pin their hopes on Italian rider Elisa Longo Borghini, who is hoping she has shaken off an illness which disrupted her preparation.

All 15 Women's World Tour teams will race, alongside British squads Drops and Team WNT – the latter including Katie Archibald, who won Olympic gold on the track in 2016.

Away from the GC battle, it is the finale in London which is seen as a coming-of-age moment for the race as the capital comes to a standstill for the event for the first time.

Race director Mick Bennett said: "Having the race finish in London on such an iconic circuit takes the event to another level, providing the ultimate platform for women's sport."