In pictures: Gateway designs

Landmark Wales aims to place works at Holyhead harbour, in Flintshire and at the Second Severn Crossing.

It is hoped the Big Lottery Fund will give �18m funding to the project.

Landmark Wales said it was "courting debate" on the plans, after a design consultant voiced strong concerns in a letter to the Western Mail.

Mike Robinson, from Cardiff, had questioned whether the 15 ideas were "worthy" enough and described the process of choosing the works as "embarrassing".

Mr Robinson said he wondered how the designs, which include a huge postcard, steel towers and a Celtic knot, had been chosen.

"I find some of them are harsh, they are irritating to the eye, they have nothing to do with Wales, they don't have the visual impact that I would like to see," he said.

In seeking to make such bold statements through public art in this way, the project is courting debate and dialogue Landmark Wales

"I think there has got to be more quality involved in the approach to the design. It is going to be an installation that future generations are going to have to look at."

He said that maintenance of the designs should also be considered and said that Antony Gormley's Angel of the North should be held up as a success story.

"The Angel of the North is the most fantastic piece because it is traditional yet modern," he said.

"I am sure it doesn't take a lot of maintenance - it is built out of a material that just wears naturally in the atmosphere and it's a huge attraction."

The sculptures are designed to be placed on routes into Wales

Mr Robinson added that the press attention over the short listed designs was "embarrassing" and that the decision should be made by "revered artists and designers" rather than a populist vote.

Landmark Wales said that Mr Robinson's opinion was "as valid as anyone's".

A spokesman said that the comments "had been noted and will be considered along with the many hundreds of other responses and comments as part of our ongoing public consultation".

"In seeking to make such bold statements through public art in this way, the project is courting debate and dialogue, inviting people to look at the short listed projects, think about them and tell us how it makes them feel.

"We welcome Mr Robinson's contribution to the consultation as it demonstrates the strength of feeling that art can elicit, and underlines why a project like Landmark Wales is so important."

Architects, artists and engineers from all over the world submitted proposals before five concepts for each location were chosen.