YORKSHIRE were among the first counties to confirm their approval of a new eight-team Twenty20 tournament – but Middlesex have delivered the first significant blow to the England and Wales Cricket Board's hopes of pressing ahead this month with their new proposal.

The White Rose club were one of the first four clubs to officially endorse the constitutional change required to pave the way for a city-based competition in 2020 which does not involve all 18 first-class counties.

Sussex, Somerset and Leicestershire were the others - but following an annual general meeting at Lord's, Middlesex spelled out this morning that they will not be following suit.

ECB chairman Colin Graves identified a "watershed moment" last month when he triggered a postal ballot to support the amendment to the national governing body's articles of association.

The vote involving all 18 first-class counties, the MCC, Minor Counties Cricket Association and 21 recreational boards must be concluded within 28 days.

Yorkshire's press release read: "The board of the Yorkshire County Cricket Club has unanimously approved a change to the ECB articles of association in order to facilitate a new T20 competition in England and Wales, which will commence in the year 2020.

"The club has attended many consultative meetings with the ECB over the last 18 months, and Gordon Hollins, the chief operating officer of the ECB, was present at a members forum in the Long Room on Friday, April 7, when members were able to discuss the implications of the new competition."

Headingley is expected to be among the venues most likely to host a team in 2020, but Yorkshire chairman Steve Denison is taking nothing for granted yet.

He said: "This is not just about a new city-based T20 competition.

"It is all to do with the ECB's 'Cricket Unleashed' strategy, which is setting out to broaden the appeal of cricket to a much wider audience.

"Cricket needs to attract boys and girls to the game through the All Stars Cricket programme, and through greater exposure on mobile devices, tablets, as well as television.

"Headingley hopes that it will be one of the chosen grounds for the new competition, but the club understands that this may well be predicated on the development of the new North/South Stand, in conjunction with Leeds Rugby."

Since the ECB's executive board resolved to dispatch the paperwork on March 28, indications were of favourable response elsewhere – until Middlesex broke ranks.

A statement on the club website read: "After consultation with members at yesterday's AGM, the board of Middlesex CCC has decided that it is unable to support the proposed changes to the articles of association of the ECB.

"These articles require stakeholders to approve the removal of the right of all 18 counties to compete in the proposed new T20 tournament from 2020 onwards."

Chairman Mike O'Farrell explained the concerns which prevent agreement for the move from a county who are tenants rather than owners of their own headquarters.

"While Middlesex is fully supportive of the creation of a new T20 tournament to drive the future of the game, we are unable to support this proposal at the current time," he said.

"Middlesex has a unique position in playing at a ground that is likely to be a host venue at the tournament, yet not benefiting from the revenues associated with that status.

"Therefore, the financial impact on Middlesex is still very uncertain and contains great risks to our current revenue streams.

"Additionally, the current governance of the ECB means that this article change creates a significant risk that counties that are not host venues for the new tournament may, in the future, be downgraded both in status and in revenue terms."

Middlesex are therefore hoping for a new pathway to 2020.

O'Farrell added: "We welcome the ECB's commitment to a further revision to its articles to provide the protections that we require - but until these commitments become legally binding, we cannot support the current change of articles of association.

"We look forward to working with the ECB in the near future to developing a proposal that alleviates our concerns and provides a solution to domestic cricket that meets all our collective objectives."

Each club will receive a £1.3million annual share of the new competition's revenue in its first four years, and to proceed the ECB needs a vote of at least 31 in favour from the 41 member organisations consulted.

Derbyshire became the fifth county to back the ECB's proposal, announcing their agreement on the club website today.