People living on Westfield Terrace and the Wakefield Civic Society all objected to plans to extend one of the houses and turn it into nine flats.

But they say they never received notice from the council of the planning committee meeting, meaning they were unable to challenge the application which was eventually approved.

Anyone involved, including objectors, can apply to speak at the committee meetings to get their views across – and protesters said the scheme would cause parking problems and would overshadow their properties. They now want the matter to be heard again.

Linda Hopper, 59, of Westfield Terrace, said: "I feel furious about the way this has been dealt with and the council seems to be burying its head in the sand – it still claims it sent the letters to us.

"But it's not a question of one resident not receiving a letter – none of us got it. We will take this as far as we have to."

The protesters have contacted their MP Mary Creagh and even the Post Office to see if there is any undelivered mail.

Ms Creagh said: "It looks like the council could be in breach of its obligations and I hope it will look again at this decision without going through a long legal process."

Angry Kenneth Stephenson, 83, of Westfield Terrace, said: "It is supposed to be a democratic society, but this is just riding roughshod over us.

"The council acknowledged our objections, but then went and had a committee meeting without us."

Wakefield Civic Society confirmed it had not received a letter about the forthcoming meeting.

Chairman Kevin Trickett added: "It's obviously a breakdown in process and we are asking for the decision to be set aside so it can be heard again and the objectors can have their views heard."

Ian Thomson, Wakefield Council's service director for planning, said: "Our records show that letters to the objectors were sent first class advising them of the committee meeting in advance. These were sent at the same time as letters to objectors for other applications to be heard at the same meeting.

"There is evidence of the receipt of these other letters because there were a number of speakers at the committee so we are uncertain how the objectors on Westfield Terrace did not receive notice when others clearly did.

"We have spoken to the objectors and the complaint is now being dealt with by the council's complaints service."