By Matt Wells BBC correspondent in New York

The first official planning options for rebuilding Lower Manhattan after the 11 September attacks are due to be revealed.

Six proposals have been commissioned by the umbrella-body which New York Governor George Pataki created to oversee the whole process - the Lower Manhattan Development Corporation (LMDC).

The plans will generate detailed and passionate discussion among New Yorkers when they appear on Tuesday

They have been shrouded in secrecy, and were guided by a complex set of financial and commercial considerations.

But several leading politicians in the city have already seen them, and begun to cast judgement.

Mayor Michael Bloomberg surprised the media by calling a rare Saturday press conference last weekend, where he made clear his own reservations.

"It's a start," he told reporters curtly.

"It's at the conceptual stage of saying, this is one of the ways we could use the space. I've got my own ideas, which I will certainly write to (planners)."

Crunch week

The plans will generate detailed and passionate discussion among New Yorkers when they appear on the LMDC website on Tuesday.

On Saturday, up to 5,000 people are expected to attend a public meeting on the options ahead, in a Midtown conference centre.

In a survey carried out for Sunday's edition of the New York Post newspaper, just under half of those canvassed said that they would like to see the twin-towers of the World Trade Center fully rebuilt.

Relatives of the victims are firmly opposed to building

Leading the way at the start of this crunch week for the whole process was New York State's most famous serving politician, Senator Hillary Clinton.

She has no direct role in the LMDC, but she used two meetings on Monday morning to outline her vision of what the priorities need to be.

First she addressed The Downtown Alliance - a consortium of interest groups keen to enlist her support and goodwill on behalf of those who live and work in the area.

Then she visited the local community which has visibly suffered the most in the wake of the towers' destruction - the people of Chinatown.

At a meeting packed with local business people, politicians and journalists in a Chinese restaurant, she distanced herself from pre-judging any options at this stage.

Emphasising that she had not seen the plans, she said: "I view this announcement on Tuesday as the beginning of the process. Not an end point, but a starting point.

"There are many people in this room, and throughout the city who have ideas that should be expressed, and the first public forums will be held on Saturday."

'Appropriate memorial'

Governor Pataki - who is the man who controls the form and speed of the whole rebuilding timetable - was openly criticised last month for saying he would never allow any building to take place on the actual sites themselves of the twin towers.

This is a view shared by many relatives of the dead, but speculation was rife that by ruling it out, some of the plans due for release on Tuesday would be obsolete before publication.

Every politician is looking for a non-controversial but specific role to play in the rebuilding of New York

I asked Senator Clinton whether she agreed with the governor, or not. The answer was acutely diplomatic:

"I am going to wait until I see the process unfold. I am certainly well aware of the strong feelings that people have. I think we should set objectives... The top of the list has to be an appropriate memorial."

The go-between

"The human imagination knows no bounds. We haven't yet seen what can come from the extraordinary creative effort that will go into this," she added.

People in Chinatown have suffered much as a result of the attacks

Every politician is looking for a non-controversial but specific role to play in the rebuilding of New York.

Senator Clinton says that her niche will be as go-between with the national government:

"My role it to try to be sure that we get federal support for whatever the plans are. That's what I will be working first and foremost to achieve."