Ed Davey has been a regular visitor to the constituency, helping volunteers canvas for the party's candidate, Helen Morgan, ahead of the vote on December 16.
In Oswestry this weekend he said he was finding real anger from voters on the doorstep over the Government.
"They feel that they have been taken for granted in what was considered a 'safe seat' and that the Government has become complacent," he said.
"Our canvassing is showing that this by-election is too close to call.
"The people of North Shropshire have been taken for granted for too long, including the farmers, businesses and pensioners.
"This month farmers will lose five per cent of their basic farm payment. Pensioners are a risk from the suspension of the triple lock and businesses are suffering from the business rates. All of this as we face rising fuel and food prices."
Mr Davey said that there was particular concern about health service issues on the doorsteps.
"I have heard harrowing accounts of waits for ambulances. More money must be spent on front line health services rather than on the bureaucracy of our NHS."
"I have heard from those we felt excluded from the furlough scheme, the self employed - driving instructors and hairdressers for example."
Parliamentary candidate, Helen Morgan, said had had the same response across the constituency, from the towns to the villages and hamlets.
"We are speaking to as many people as we can including those living in the hamlets that feel left out and forgotten."