An Essex-born woman who vanished while walking her dog has “two little girls that need their mummy home”, her boyfriend said as a major search continues.

Nicola Bulley, 45, went missing on Friday morning – with her mobile phone found on a bench near to where she was last seen on a towpath by the River Wyre in St Michael’s on Wyre, Lancashire.

Her mobile phone was still connected to a conference call when it was found, police said.

In an update on Monday, police said they are keeping an “open mind” about what happened but do not believe Ms Bulley was attacked.

The dog, springer spaniel Willow, was found loose between the river and bench.

Ms Bulley, a mortgage adviser, has lived in Lancashire for 25 years but is originally from near Chelmsford, and has a southern accent.

Her partner Paul Ansell, speaking from the family home in Inskip, Lancashire, said he spent all of Sunday searching for the mother-of-two.

The engineer, who has been in a relationship with Ms Bulley for 12 years, said: “It is just perpetual hell. It is just utter disbelief.

“We are living through this but it doesn’t feel real.

“All we can say is we need to find her. She’s got two little girls that need their mummy home.

“We have got to get some good news now.”

Mr Ansell said he or Ms Bulley, also known as Nikki, would drop the children, aged nine and six, off at a local primary school before taking Willow for a walk along the river nearby.

Ms Bulley did the school run before heading for the dog walk on Friday, police indicated.

“I got a call from the school regarding somebody who had found Willow, and Nikki’s phone and the dog lead and harness on the bench,” Mr Ansell, who then called the police, said.

“We take the kids to school and take the dog down there – either myself or Nikki – nearly every day.”

She was last seen by a member of the public at about 9.15am, police said.

Superintendent Sally Riley from Lancashire Police told the Mirror that Ms Bulley’s phone was still on an active call when it was found: “It was on a meeting call, and that was still live. It was connected to the conference call and that hadn’t been terminated.”

The officer told a press conference that fears for Ms Bulley are growing as time passes.

She said: “The police are keeping a really open mind about what could have happened but we do believe that the likelihood is that Nicola has gone missing and this is not a crime inquiry.

“We’ve mounted a really intensive operation to try to find Nicola.

“We’ve got a large area to search.

“People do go missing but clearly as time goes on we become more and more concerned for Nicola.

“But we’re very much hoping that we will find something to try to bring her home safe and well soon.

“We appeal for anyone who may have been driving through the village of St Michael’s last Friday morning at about 9.15am or who may have dashcam footage that could be of use to us, or people who may have been dog-walking in the area or on the tow path, to come forward.

“They can ring 101 or, if they have a sighting of Nicola, 999.”

Ms Bulley is described as white, 5ft3in, with light brown shoulder-length hair.

At the time of her disappearance she was wearing a long black gilet jacket with a hood, black jeans and olive green ankle wellington boots.

Her hair was in a ponytail.

Searches have been carried out by Lancashire Police, using a helicopter, drones and dogs with support from Lancashire Fire and Rescue Service, Bowland Pennine Mountain Rescue team and the North West Underwater Search Team.

Locals have also organised searches in the area.

Anybody with information can call 101, quoting log 473 of January 27, or Crimestoppers anonymously on 0800 555 111.